modernized test suite

[bmos]

Need to merge #312 to resolve testing issues first to:

• fix doc building
• see if tests pass on all versions

Highlights

• Fix argument deprecation test on windows hosts
• Resolve all but one DeprecationWarning posted during test runs (the last one comes from the program code, not testing)
• Replace unittest with pytest wherever possible
• Consolidate some tests via parameterization
• Speed up the two tests that were taking a long time (should save 20+ seconds per test run)
• Add additional test to ensure open_tunnel's block_on_close argument posts DeprecationWarning

[coveralls]

coverage: 92.113% (+0.4%) from 91.667%
when pulling f9baf62 on bmos:tests
into dc07328 on pahaz:master.