Add support from_pandas for Index/MultiIndex.

[ueshin]

No description provided.

[codecov-io]

Codecov Report

Merging #1170 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1170      +/-   ##
==========================================
- Coverage   95.21%   95.21%   -0.01%     
==========================================
  Files          35       35              
  Lines        7067     7066       -1     
==========================================
- Hits         6729     6728       -1     
  Misses        338      338

Impacted Files	Coverage Δ
databricks/koalas/namespace.py	87.57% <100%> (+0.07%)	⬆️
databricks/koalas/window.py	97.09% <0%> (-0.02%)	⬇️
databricks/koalas/series.py	96.43% <0%> (-0.01%)	⬇️
databricks/koalas/base.py	96.34% <0%> (ø)	⬆️
databricks/koalas/groupby.py	91.6% <0%> (ø)	⬆️
databricks/koalas/frame.py	97.01% <0%> (ø)	⬆️

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