BUG: rolling_count() and expanding_*() with zero-length args; rolling/expanding_apply() with min_periods=0
Made line comments work with whitespace delim and custom line terminator
Added a release note
Merge pull request #8122 from amras1/linecomments-whitespace-delim

Made line comments work with delim_whitespace and custom line terminator
Merge pull request #8059 from seth-p/rolling_count

BUG: rolling_count() and expanding_*() with zero-length args; rolling/expanding_apply with min_periods=0
BUG: add 'import warnings' statement in panel.py (GH8152)
ENH: allow axis argument to append / move append code to generic.py (GH8295)
a simple test for Panel, which raises NotImplementedError
a method `append` moved from frame.py to generic.py
test cases for DataFrame.append moved from tests_frame.py to tests_generic.py

test cases for DataFrame.append moved from tests_frame.py to tests_generic.py #1

test cases for DataFrame.append moved from tests_frame.py to tests_generic.py #2
test cases for Series.append moved from tests_series.py to tests_generic.py
`append` in generic.py passes `axis` argument. And added corresponding test case