Implement Index.drop

[RainFung]

Implement Index.drop by using spark isin API

[codecov-io]

Codecov Report

Merging #1117 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master   #1117      +/-   ##
=========================================
+ Coverage   95.19%   95.2%   +<.01%     
=========================================
  Files          35      35              
  Lines        7075    7086      +11     
=========================================
+ Hits         6735    6746      +11     
  Misses        340     340

Impacted Files	Coverage Δ
databricks/koalas/missing/indexes.py	100% <ø> (ø)	⬆️
databricks/koalas/indexes.py	96.61% <100%> (+0.15%)	⬆️

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[softagram-bot]

Softagram Impact Report for pull/1117 (head commit: 0979130)

⚠️ Copy paste found

ℹ️ test_indexes.py: Copy paste fragment on line 30 shared with ../test_dataframe.py, ../test_numpy_compat.py:

    @property
    def pdf(self):
        return pd.DataFrame({
            'a': [1, 2, 3, 4, 5, 6, 7, 8, 9],
            'b': [4, 5, 6, 3, 2, 1, ...(truncated 160 chars)

ℹ️ indexes.py: Copy paste fragment inside the same file on lines 747, 1118:

            raise NotImplementedError(
                \"Doesn't support symmetric_difference between Index & MultiIndex for now\")

        sdf_self = self._kdf._s...(truncated 477 chars)

Now that you are on the file, it would be easier to pay back some tech. debt.

⭐ Change Overview

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• Permalink: Full report for pull/1117

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