We add this dependancy to thumbor for no use other than making an
import possible in one of the upcoming commits. Basically we wanted to
import LOCAL_UPLOADS_DIR from zproject.prod_settings or
zproject.dev_settings and prod_settings_template.py imports
django-auth-ldap (which depends on python-ldap and django).
This seems counterproductive, but it makes it possible for us to save
significant thumbor server startup time that would have been consumed
in `get-django-setting`, and once thumbor supports Python 3, we'll
probably be merging the virtualenvs anyway (in which case this change
would become a no-op).
This commit renames various source requirements files like `dev.txt`,
`mypy.txt` etc to `dev.in`, `mypy.in` etc and various locked requirements
files like `dev_lock.txt`, `mypy_lock.txt` etc to `dev.txt`, `mypy.txt`
etc. This will help in emphasizing to the user that *.in are actually
input to `update-locked-requirements` tool which should be run after
updating any of these.