Revert "Fix the docs requirements file"

This reverts commit d081bf0.

ReadTheDocs attempts to build the sphinx documentation with a working
directory set to the root of the errbot project/repo itself. That means
it needs `.` to refer to errbot's own `setup.py` file, not `./..`.

It's a bit confusing because it means you can't `pip install -r
requirements.txt` from the docs folder, but have to do so from one level
up. :( I don't see a good way around that though (if anyone has a better
solution, I'm all ears).

Author: zoni

docs/requirements.txt

@@ -4,7 +4,7 @@ sphinx>=1.2
 # is fixed and included into a new release.
 https://github.com/zoni/sphinx-autodoc-annotation/archive/issue-2.zip
 
--e ../.
+-e .
 sleekxmpp
 irc
 pyfire