General print statement cleanup.
Merge pull request #4973 from alefnula/print-cleanup

CLN: General print statement cleanup.
TST/CLN: pare down the eval test suite
Merge pull request #4974 from cpcloud/eval-test-paredown

TST/CLN: pare down the eval test suite
FIX: JSON support non C locales
FIX: resample to single group with custom function
Merge pull request #4494 from Komnomnomnom/resample-sing-grp-bug

FIX: resample to single group with custom function
Merge pull request #4976 from Komnomnomnom/json-locale-fix

FIX: JSON support for non C locales
Fixed _format_labels in tile.py for np.inf.

Since the fractional part of np.inf is 0.0 it is enough to change the
formatter string in this case to the (nearly) equivalent "%.0f".
Merge pull request #4954 from filmor/format-labels-fix

BUG: Fixed _format_labels in tile.py for np.inf.
ENH: add statsmodels wheel

Also removes the statsmodels/pandas faking part of ci/install.sh by using a
statsmodels wheel
CLN: proper version checking for statsmodels testWLS
Merge pull request #4981 from cpcloud/statsmodels-ci-addition

CI/ENH: test against an older version of statsmodels