Mask calibrated GOES HRIT data

[pnuu]

This PR masks data when loading calibrated GOES HRIT data.

• Closes Data is not masked when loading calibrated GOES HRIT data #379
• Tests added
• Tests passed
• Passes git diff origin/master **/*py | flake8 --diff

[coveralls]

Coverage decreased (-0.002%) to 69.083% when pulling 7f02be6 on bugfix-hrit_goes-masking into ade4f95 on master.

[codecov]

Codecov Report

Merging #380 into master will decrease coverage by <.01%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##           master     #380      +/-   ##
==========================================
- Coverage   69.08%   69.08%   -0.01%     
==========================================
  Files         123      123              
  Lines       15724    15726       +2     
==========================================
+ Hits        10863    10864       +1     
- Misses       4861     4862       +1

Impacted Files	Coverage Δ
satpy/readers/hrit_goes.py	50.67% <50%> (-0.01%)	⬇️

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[pnuu]

There seems to be still something that causes IR data to be masked on areas where there's no VIS data.

[djhoese]

@pnuu Are you still having issues with this? Should I wait to merge this?

[pnuu]

The problem I mentioned is actually the one in #383, just forgot to reference that issue. The masking is otherwise OK with this PR.

[djhoese]

So I can merge this?

[pnuu]

Yes, go ahead.