Set tag
Merge pull request #33 from fromYukki/feature-set_tag

New tag `set`
Update .travis.yml
Update .travis.yml
Fixes race condition in benchmark.
Merge branch 'master' of github.com:flosch/pongo2
Update .travis.yml
Update README.md
Fixes a few bugs w.r.t. utf8-handling in filters. Fixes #34 and #37
Merge branch 'master' of github.com:flosch/pongo2