Removed "...::Web Environment::Mozilla" classifier

Removed the `'Environment :: Web Environment :: Mozilla',` from `classifiers` in `setup.py` as I see no particular reason to signal/limit use of Bleach to a 'Mozilla' web environment only.

Perhaps it is my limited understanding of the Trove classifiers... in which case you can simply close this PR as uneducated, no worries :-)
Merge pull request #115 from mdxs/patch-2

Removed "...::Web Environment::Mozilla" classifier