Added route for filters

Issue #33 on upstream
updated to API v4. Remote repo issue #35
Merge pull request #34 from Dwaynekj/issue/33

Added route for filters
Merge branch 'issue/35' of github.com:Dwaynekj/axosoft-python into Dwaynekj-issue/35
Merge branch 'develop' of github.com:ckaznocha/axosoft-python into Dwaynekj-issue/35
Closes #35
fix python 3.x import error
Use built in set()
Merge pull request #37 from ckaznocha/Dwaynekj-issue/35

Dwaynekj issue/35
Merge pull request #38 from ckaznocha/develop

Develop