Update README.md

Updated the name of the requirements doc to requirements.txt instead of requirements/mozwebqa.txt
Merge pull request #75 from terrameijar/master

Updated Readme to include correct text file
fix @stephendonner's intriguing pedantic insights
update make_absolute_paths(), s/dirs/paths/ & s/dir/path/
Merge pull request #76 from m8ttyB/anon_200

Anon 200
xfail
update
Merge pull request #78 from AndreiH/xfail

xfail
resolve merge conflicts