Merge pull request #7836 from cpcloud/read-html-test-fix

TST/BUG: html tests not skipping properly if lxml is not installed
COMPAT/TST: add assertRaises and assertRaisesRegex to the base TestCase to avoid confusion
BUG: _flex_binary_moment() doesn't preserve column order or handle non-unique columns
Merge pull request #7738 from seth-p/flex_binary_moment_column_order

BUG: _flex_binary_moment() doesn't preserve column order or handle multiple columns with the same label
Merge pull request #7697 from sinhrks/offsetnano

BUG/PERF: offsets.apply doesnt preserve nanosecond
BUG: DTI.value_counts doesnt preserve tz
Merge pull request #7735 from sinhrks/value_counts_tz

BUG: DTI.value_counts doesnt preserve tz
BUG: Series.__iter__ not dealing with category type well (GH7839)
Merge pull request #7842 from jreback/cat_iter

BUG: Series.__iter__ not dealing with category type well (GH7839)
BUG: PeriodIndex.unique results in Int64Index
DOC: add link to SettingWithCopy warning/error message (GH7658)
COMPAT: SettingWithCopy will now warn when slices which can generate views
        are then set
Merge pull request #7845 from jreback/setting_with_copy

COMPAT: SettingWithCopy will now warn when slices which can generate views are then set
Merge pull request #7843 from sinhrks/punique

BUG: PeriodIndex.unique results in Int64Index
BUG/VIS: rot and fontsize are not applied to minor ticks
CLN: cln tslib, frequencies
BUG: don't force date parsing in read_html

Necessitates the deprecation of the ``infer_types`` argument.
Merge pull request #7851 from cpcloud/read-html-date-parsing

BUG: fix greedy date parsing in read_html
Merge pull request #7854 from sinhrks/tslib_cln

CLN: Clean tslib, frequencies import
Merge pull request #7844 from sinhrks/minor_rot

BUG/VIS: rot and fontsize are not applied to timeseries plots