Fix existing flake8 errors and add flake8 check and verbose flag to CI

[micahkim23]

Closes #234

[spencerahill]

Thanks @micahkim23

So we're getting an error message on the git diff call: https://travis-ci.org/spencerahill/aospy/jobs/304612704#L1101. From that log:

$ git diff upstream/develop **/*py | flake8 --diff --exit-zero || true
fatal: ambiguous argument 'upstream/develop': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:

But I now see that xarray's tests (from which we stole that line, replacing upstream/master with upstream/develop have the exact same error: https://travis-ci.org/pydata/xarray/jobs/304072446#L4089

The command does work on my local machine, however (with upstream/develop), in that I don't get this error message. But in playing around with it briefly, I couldn't actually trigger a non-zero exit status. I'm new to git diff, so I doubt it's something too difficult. But we should get this sorted out before merging this.

@micahkim23 so you might have to read up on git diff a bit to figure this out.

[spencerkclark]

Is it simply that there is no remote named upstream on Travis? Agreed that we should try to fix this.

I missed something that I think we should try to fix.

[spencerkclark]

Naively I might try adding something like:

- git remote add upstream https://github.com/spencerahill/aospy.git

before the following line in our .travis.yml:

aospy/.travis.yml

Line 44 in b3bbd20

- py.test aospy --cov=aospy --cov-report term-missing

[spencerahill]

@spencerkclark good idea.

Separately, see #238 re: the test failures

[micahkim23]

I think the appveyor failures will be fixed with #240 and the commit that closes the files in test_calc_basic.py. Should we wait until that pr is merged or should I just make the same change here?

[spencerkclark]

Thanks @micahkim23! If it's not too much trouble, go ahead and fix the failing Appveyor tests following a3a3753. It will be good to get the flake8 check in before we merge further PR's. I may do some more work in #240, so it might be open a bit longer (and I'm totally cool merging my branch with the latest develop branch once this gets merged).

[spencerahill]

@micahkim23 this is great!

go ahead and fix the failing Appveyor tests following a3a3753. It will be good to get the flake8 check in before we merge further PR's

I agree with this. Excited to merge once this is addressed.

[micahkim23]

Now the only appveyor failure is the issue described in #238.

[spencerahill]

Now the only appveyor failure is the issue described in #238.

Exactly. So in it goes! Thanks @micahkim23 for the heavy lifting and @spencerkclark for the review