BUG: remove six import
Merge pull request #4250 from cpcloud/six-fix

BUG: remove six import
TST: no need for flavor testing in skip

Skip bs4 tests when 4.2.0 is found.
DOC: add v0.13.0.txt release notes file (but not to the index yet)
Merge pull request #4257 from cpcloud/read-html-flavor-attr

TST: no need for flavor testing in skip
BLD/TST/CI: add script to show skipped tests at the end of a build
Merge pull request #4262 from cpcloud/print-skipped-tests

BLD/TST/CI: add script to show skipped tests at the end of a build
TST/BLD: add testing for bad bs4 version
TST: add message to nose.SkipTest
Merge pull request #4259 from cpcloud/add-bad-bs4-version-to-travis

TST/BLD: add proper skips for bad bs4 version
CLN: define __hash__ directly for _NaT; needed for some builds on py3k
TST: skip if no html5lib since bs4 needs it
TST/CI: add scikits.timeseries wheel back
Merge pull request #4267 from cpcloud/html5lib-fix

TST: skip if no html5lib since bs4 needs it
Merge pull request #4269 from jreback/nat_py3

CLN: define __hash__ directly for _NaT; needed for some builds on py3k
Merge pull request #4270 from cpcloud/scikits-wheel

TST/CI: add scikits.timeseries wheel back