Make PyHive work with Python 3.7 async

[betodealmeida]

In Python 3.7 async became a keyword, breaking PyHive's execute method. This PR fixes it by allowing either async or async_ to be passed as a keyword argument, in order to preserve backwards compatibility.

This fixes #148.

[codecov-io]

Codecov Report

Merging #232 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #232      +/-   ##
==========================================
+ Coverage   93.92%   93.94%   +0.02%     
==========================================
  Files          14       14              
  Lines        1482     1487       +5     
  Branches      157      159       +2     
==========================================
+ Hits         1392     1397       +5     
  Misses         64       64              
  Partials       26       26

Impacted Files	Coverage Δ
pyhive/hive.py	87.4% <100%> (+0.25%)	⬆️
pyhive/tests/test_hive.py	97.74% <100%> (ø)	⬆️

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[betodealmeida]

Ping @jingw

[gsilk]

Thanks for the fix! Apologies for the delay in merging.

[betodealmeida]

Thanks, @gsilk! I signed the Dropbox Contributor License Agreement.

[gsilk]

New release is out: https://pypi.org/project/PyHive/0.6.1/

Let me know if there are any problems! Thanks

[freephys]

1. from pyhive import presto
   async_ not found on latest pyhive
   How to solve it
2. How to run multuple query in parallel with pyhive?
   share same cursor or create multiple cursor?

Thanks

[betodealmeida]

1. from pyhive import presto
   async_ not found on latest pyhive
   How to solve it

2. How to run multuple query in parallel with pyhive?
   share same cursor or create multiple cursor?

@freephys do you mind creating issues for these? Also, can you give more details on (1)?