Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Move Piwik provisioning into a Celery task.
Add Piwik tasks to source control.
Move storage setup into separate Celery import.
Defer Celery tasks until request teardown.
Show statistics on private nodes.
Revert preprocess request in base test cases.
Merge branch 'develop' of github.com:CenterForOpenScience/osf into develop
Start the first function
Move Celery setup and teardown into signals.
Handle hgrid exception raised when dropbox token is invalid

An unhandled error occurs if a user tries to drag and
drop a file into a linked dropbox folder when their
credentials are invalid.

Re-raise the dropbox.rest.ErrorResponse [401] as
an HTTPError. If the error is not 401, raise as
400.
Test upload dropbox file with invalid token throws error

Also change error message language to include a
more general "check your project settings"
to apply to both the dropbox account owner
and any contributors.
Add functionality described in docstrings to GitHub.branches()
Passing a branch into GitHub.branches() should provide a single branch
as the return value. As originally written, that argument was ignored,
and a list of ALL branches was returned. I changed it so that, if that
argument is passed in, a one-item list is passed back, with the specified
branch.

I went with a single-item list because check_permissions in github/utils.py
assumed it was receiving a list (specifically) and (generally) because it
made the return values more consistent.
Merge branch 'develop' of github.com:CenterForOpenScience/osf into feature/github-permissions-tests
Add tests for github.utils.check_permissions
Re-add utils.py; accidentally deleted it