release: 0.9.3

[mdonadoni]

TODO:

• Merge models: improve indexes #213
• Change date in CHANGES.rst

[codecov]

Codecov Report

Merging #215 (6cfee4b) into master (74737b8) will not change coverage.
The diff coverage is 0.00%.

❗ Current head 6cfee4b differs from pull request most recent head 184d81b. Consider uploading reports for the commit 184d81b to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #215   +/-   ##
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  Coverage   74.50%   74.50%           
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  Files           7        7           
  Lines         902      902           
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  Hits          672      672           
  Misses        230      230           

Files	Coverage Δ
reana_db/version.py	0.00% <0.00%> (ø)

[tiborsimko]

Cosmetics: suggested changes for the release news:

• Changes the Workflow table to replace the run_number column with two new columns run_number_major and run_number_minor in order to allow for more than nine restarts of user workflows.
• Changes the names of database table, column, index and key constraints in order to follow the SQLAlchemy upstream naming conventions everywhere.
• Changes several database index definitions in order to improve performance of most common database queries.