Repository: sktime/sktime

Issue:
Rename master branch to main 
I suggest to rename our current `master` branch to the new GitHub standard name `main`.  

More details on why and what has to be done here: https://github.com/alan-turing-institute/the-turing-way/issues/1210

### What do I have to do as an sktime contributor now that the renaming has happened?
Any collaborator with a local clone of the repository will need to update the clone. From the local clone of the repository on a computer, run the following commands to update the name of the default branch:
```
git branch -m master main
git fetch origin
git branch -u origin/main main
```

More info at https://docs.github.com/en/github/administering-a-repository/renaming-a-branch
Rename master branch to main 
I suggest to rename our current `master` branch to the new GitHub standard name `main`.  

More details on why and what has to be done here: https://github.com/alan-turing-institute/the-turing-way/issues/1210

### What do I have to do as an sktime contributor now that the renaming has happened?
Any collaborator with a local clone of the repository will need to update the clone. From the local clone of the repository on a computer, run the following commands to update the name of the default branch:
```
git branch -m master main
git fetch origin
git branch -u origin/main main
```

More info at https://docs.github.com/en/github/administering-a-repository/renaming-a-branch


Discussion:
@mloning In which files we need to rename it can you please mention?
Hi @96RadhikaJadhav - take a look at the linked issue from The Turing Way, they provide all the details. In terms of in file references to `master`, I'd do a search over the entire repository to find out where we refer "master". Does that help?
@mloning Can I do it ? 
Hi @ayan-biswas0412, let's check: @96RadhikaJadhav are you still working on this? If not, @ayan-biswas0412 can do it! 
@mloning I have a question just for my knowledge enhancement , what I have to do with the script which is given in your mentioned link, that python script https://gist.github.com/sgibson91/44a1c3a6bbf34257dbdbb621a98dab0d , Can you please solve my doubt
@mloning  For now, I'm bit busy with other issues. It may take some time for me to grab this one. Meanwhile, @ayan-biswas0412  you can work on it if you want. 
Thank You.
> @mloning For now, I'm bit busy with other issues. It may take some time for me to grab this one. Meanwhile, @ayan-biswas0412 you can work on it if you want.
> Thank You.

great I can do it but @mloning for changing the base branch I think I have to get the repository access as contributor
@ayan-biswas0412, I think we can simply use the "rename" option that is also mentioned in the link - the readme asserts that this will also rename all references incl PR targets.
https://github.com/github/renaming#renaming-existing-branches

@mloning, that´s a one-click-thing in the admin config, can you confirm that it looks to you as well that we don´t need any help for this (since it´s a one-button-action)?

(I´m not doing anything since I might be missing something obvious here)
... anything about the CI set-up that will break, maybe?
> @ayan-biswas0412, I think we can simply use the "rename" option that is also mentioned in the link - the readme asserts that this will also rename all references incl PR targets.
> https://github.com/github/renaming#renaming-existing-branches
> 
> @mloning, that´s a one-click-thing in the admin config, can you confirm that it looks to you as well that we don´t need any help for this (since it´s a one-button-action)?
> 
> (I´m not doing anything since I might be missing something obvious here)

I also feel same like you that it is a one click action in the admin config
As Sarah summarised in the linked issue: Things that the new feature won't do:

- [ ] Rewrite our CI files to the correct branch
- [ ] Update any docs

So as suggested above, I'd do a search over the entire repository to find out where we refer "master" and replace that with "main". 

I'm happy to make the changes in the repo settings that require admin access. 
> As Sarah summarised in the linked issue: Things that the new feature won't do:
> 
> * [ ]  Rewrite our CI files to the correct branch
> * [ ]  Update any docs
> 
> So as suggested above, I'd do a search over the entire repository to find out where we refer "master" and replace that with "main".
> 
> I'm happy to make the changes in the repo settings that require admin access.

I can do the changes in the entire repo and change the master to main , please can I do that ? I will be highly obliged
@ayan-biswas0412 Sure, I'd start with the docs (including docs like CONTIRBUTING.md) and open a PR to see if everything passes. Changing the CI files will likely break the CI on the PR, so let's start with the docs. 
@mloning In which files we need to rename it can you please mention?
Hi @96RadhikaJadhav - take a look at the linked issue from The Turing Way, they provide all the details. In terms of in file references to `master`, I'd do a search over the entire repository to find out where we refer "master". Does that help?
@mloning Can I do it ? 
Hi @ayan-biswas0412, let's check: @96RadhikaJadhav are you still working on this? If not, @ayan-biswas0412 can do it! 
@mloning I have a question just for my knowledge enhancement , what I have to do with the script which is given in your mentioned link, that python script https://gist.github.com/sgibson91/44a1c3a6bbf34257dbdbb621a98dab0d , Can you please solve my doubt
@mloning  For now, I'm bit busy with other issues. It may take some time for me to grab this one. Meanwhile, @ayan-biswas0412  you can work on it if you want. 
Thank You.
> @mloning For now, I'm bit busy with other issues. It may take some time for me to grab this one. Meanwhile, @ayan-biswas0412 you can work on it if you want.
> Thank You.

great I can do it but @mloning for changing the base branch I think I have to get the repository access as contributor
@ayan-biswas0412, I think we can simply use the "rename" option that is also mentioned in the link - the readme asserts that this will also rename all references incl PR targets.
https://github.com/github/renaming#renaming-existing-branches

@mloning, that´s a one-click-thing in the admin config, can you confirm that it looks to you as well that we don´t need any help for this (since it´s a one-button-action)?

(I´m not doing anything since I might be missing something obvious here)
... anything about the CI set-up that will break, maybe?
> @ayan-biswas0412, I think we can simply use the "rename" option that is also mentioned in the link - the readme asserts that this will also rename all references incl PR targets.
> https://github.com/github/renaming#renaming-existing-branches
> 
> @mloning, that´s a one-click-thing in the admin config, can you confirm that it looks to you as well that we don´t need any help for this (since it´s a one-button-action)?
> 
> (I´m not doing anything since I might be missing something obvious here)

I also feel same like you that it is a one click action in the admin config
As Sarah summarised in the linked issue: Things that the new feature won't do:

- [ ] Rewrite our CI files to the correct branch
- [ ] Update any docs

So as suggested above, I'd do a search over the entire repository to find out where we refer "master" and replace that with "main". 

I'm happy to make the changes in the repo settings that require admin access. 
> As Sarah summarised in the linked issue: Things that the new feature won't do:
> 
> * [ ]  Rewrite our CI files to the correct branch
> * [ ]  Update any docs
> 
> So as suggested above, I'd do a search over the entire repository to find out where we refer "master" and replace that with "main".
> 
> I'm happy to make the changes in the repo settings that require admin access.

I can do the changes in the entire repo and change the master to main , please can I do that ? I will be highly obliged
@ayan-biswas0412 Sure, I'd start with the docs (including docs like CONTIRBUTING.md) and open a PR to see if everything passes. Changing the CI files will likely break the CI on the PR, so let's start with the docs. 

Resolving patch:
diff --git a/build_tools/make_release.py b/build_tools/make_release.py
--- a/build_tools/make_release.py
+++ b/build_tools/make_release.py
@@ -232,14 +232,14 @@ def action(self, context):
 
 class PushTagToGitHub(Step):
     def action(self, context):
-        self.do_cmd("git push -u --tags origin master")
+        self.do_cmd("git push -u --tags origin main")
 
 
 def main():
     colorama.init()
     steps = [
         # prepare and run final checks
-        ConfirmGitStatus(branch="master"),
+        ConfirmGitStatus(branch="main"),
         MakeClean(),
         UpdateVersion(),
         CheckVersionNumber(),
diff --git a/docs/source/conf.py b/docs/source/conf.py
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -39,7 +39,7 @@
 if ON_READTHEDOCS:
     READTHEDOCS_VERSION = os.environ.get("READTHEDOCS_VERSION")
     if READTHEDOCS_VERSION == "latest":
-        CURRENT_VERSION = "master"
+        CURRENT_VERSION = "main"
 
 # -- General configuration ---------------------------------------------------
 
@@ -71,7 +71,7 @@
     ".md": "markdown",
 }
 
-# The master toctree document.
+# The main toctree document.
 master_doc = "index"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
@@ -101,7 +101,7 @@
 def linkcode_resolve(domain, info):
     def find_source():
         # try to find the file and line number, based on code from numpy:
-        # https://github.com/numpy/numpy/blob/master/doc/source/conf.py#L286
+        # https://github.com/numpy/numpy/blob/main/doc/source/conf.py#L286
         obj = sys.modules[info["module"]]
         for part in info["fullname"].split("."):
             obj = getattr(obj, part)
@@ -227,7 +227,7 @@ def adds(pth):
 # add Binder launch buttom at the top
 CURRENT_FILE = "{{ env.doc2path( env.docname, base=None) }}"
 
-# make sure Binder points to latest stable release, not master
+# make sure Binder points to latest stable release, not main
 BINDER_URL = f"https://mybinder.org/v2/gh/alan-turing-institute/sktime/{CURRENT_VERSION}?filepath={CURRENT_FILE}"  # noqa
 nbsphinx_prolog = f"""
 .. |binder| image:: https://mybinder.org/badge_logo.svg


Test patch: