[AIRFLOW-5446] Rewrite Google KMS Hook to Google Cloud Python

[TobKed]

Use google-clooud-kms library in KMS Hook

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  • https://issues.apache.org/jira/browse/AIRFLOW-5446
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Tests

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[potiuk]

Strange - for some reason the PR has started but there is no check in the conversation here ???? Really strange...

[mik-laj]

Travis likes to make surprises.

[codecov-io]

Codecov Report

Merging #6065 into master will decrease coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #6065      +/-   ##
==========================================
- Coverage   80.03%   80.02%   -0.02%     
==========================================
  Files         594      594              
  Lines       34748    34763      +15     
==========================================
+ Hits        27812    27820       +8     
- Misses       6936     6943       +7

Impacted Files	Coverage Δ
airflow/gcp/hooks/kms.py	100% <100%> (ø)	⬆️
airflow/contrib/operators/bigquery_operator.py	92.94% <0%> (-0.78%)	⬇️
airflow/contrib/hooks/bigquery_hook.py	70.33% <0%> (-0.41%)	⬇️
airflow/gcp/example_dags/example_bigquery.py	100% <0%> (ø)	⬆️
airflow/contrib/operators/bigquery_to_gcs.py	93.75% <0%> (+0.2%)	⬆️
airflow/contrib/operators/bigquery_to_bigquery.py	93.54% <0%> (+0.21%)	⬆️
...ontrib/operators/bigquery_table_delete_operator.py	92.3% <0%> (+0.3%)	⬆️
airflow/contrib/operators/bigquery_get_data.py	84.21% <0%> (+0.42%)	⬆️
...ow/contrib/operators/bigquery_to_mysql_operator.py	74% <0%> (+0.53%)	⬆️

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