chore: release 0.44.0

[release-please]

🤖 I have created a release *beep* *boop*

0.44.0 (2021-04-23)

Features

• support self-signed JWT flow for service accounts (#774) (89d6f35)

Bug Fixes

• enable GAPIC metadata generation (#843) (697816c)

---

This PR was generated with Release Please. See documentation.

[codecov]

Codecov Report

Merging #842 (4cdbb39) into master (7c185e8) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #842   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           26        27    +1     
  Lines         1608      1653   +45     
  Branches       328       337    +9     
=========================================
+ Hits          1608      1653   +45     

Impacted Files	Coverage Δ
gapic/schema/metadata.py	100.00% <ø> (ø)
gapic/utils/case.py	100.00% <ø> (ø)
gapic/utils/reserved_names.py	100.00% <ø> (ø)
gapic/generator/generator.py	100.00% <100.00%> (ø)
gapic/schema/api.py	100.00% <100.00%> (ø)
gapic/schema/wrappers.py	100.00% <100.00%> (ø)
gapic/utils/__init__.py	100.00% <100.00%> (ø)
gapic/utils/checks.py	100.00% <100.00%> (ø)
gapic/utils/options.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 697816c...4cdbb39. Read the comment docs.

[yoshi-automation]

Release is at https://github.com/googleapis/gapic-generator-python/releases/tag/v0.44.0