Prepare PySpark 3 for dev purpose

[HyukjinKwon]

I use the manual build version of PySpark for development. As of apache/spark@ee8d661, we need some changes accordingly.

[softagram-bot]

Softagram Impact Report for pull/1181 (head commit: f7138f2)

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[codecov-io]

Codecov Report

Merging #1181 into master will increase coverage by 1.32%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master    #1181      +/-   ##
==========================================
+ Coverage   93.91%   95.24%   +1.32%     
==========================================
  Files          35       35              
  Lines        7097     7105       +8     
==========================================
+ Hits         6665     6767     +102     
+ Misses        432      338      -94

Impacted Files	Coverage Δ
databricks/koalas/internal.py	95.74% <60%> (-0.8%)	⬇️
databricks/koalas/typedef.py	82.92% <71.42%> (-0.83%)	⬇️
databricks/conftest.py	98% <0%> (+4%)	⬆️
databricks/koalas/__init__.py	85.1% <0%> (+6.38%)	⬆️
databricks/koalas/usage_logging/usage_logger.py	100% <0%> (+50%)	⬆️
databricks/koalas/usage_logging/__init__.py	97.29% <0%> (+72.97%)	⬆️

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[HyukjinKwon]

I'm merging this for my dev :-).