TST: suppress gratuitous warnings
VIS: Hide labels for NaN/zeros in boxplt

[ci skip]
CLN: pep8 clean up of sql.py
TST:  test_precision_conversion on windows fix (GH8324)
Merge pull request #8340 from jorisvandenbossche/sql-pep8

CLN: pep8 clean up of sql.py
DOC: move trellis under visualization.rst
BUG: Work-around openpyxl-2.1.0 NumberFormat removal
Merge pull request #8356 from jreback/excel_fix

BUG: Work-around openpyxl-2.1.0 NumberFormat removal
ENH/BUG: allow timedelta resamples
Merge pull request #8345 from jreback/resample

ENH/BUG: allow timedelta resamples
DOC: timedelta resample docs
Merge pull request #8353 from TomAugspurger/trellis-doc

DOC: move trellis under visualization.rst
BUG: Bug in alignment with TimeOps and non-unique indexes (GH8363)
Merge pull request #8364 from jreback/datetime_ops

BUG: Bug in alignment with TimeOps and non-unique indexes (GH8363)
BUG: rolling_window() properly averages weights in mean=True mode; removed scikits-timeseries dependency for testing; added further tests for rolling_window()
Merge pull request #8238 from stahlous/win_weights

BUG: normalize rolling_window() weights, remove scikits-timeseries dependency for testing
BUG/COMPAT: set tz on DatetimeIndex on pickle reconstruction (GH8367)
BUG: OLS with clustering and nw_lags does not error (GH5884)

Added statement to raise ValueError when OLS is run with clustering and
Newey-West adjustments. Closes GH5884.
BUG: to_clipboard output formatting (GH8305)
Merge pull request #8370 from jreback/tz_pickle

BUG/COMPAT: set tz on DatetimeIndex on pickle reconstruction (GH8367)