Get rid of EL4T in Makefile
Remove submodule tools/el4t
Use the latest version of carton

Now carton supports 23 natively
Add ert to development dependency
export EMACS in Makefile
Rerun "make elpa" when Carton is updated
Merge branch 'clean-carton'
Add jedi:pop-to-epc-buffer
Add --log-traceback to jediepcserver.py

Previously, traceback is included when logging to a file.  Now it
is possible to include traceback in stderr output.
Require epc>=0.0.4
Add jedi:toggle-log-traceback command
Document "How to get traceback"
Merge branch 'easy-traceback'
Bump to 0.1.3alpha2
Rename jedi:show-jedi-version to jedi:show-version-info

and test it and document it
Include emacs and jedi version in jedi:show-version-info
Add CONTRIBUTING.md
Add how to update document
Improve "How to get traceback" section
Fix code in "How to get traceback" section

thanks to @lxsameer (see #67)