MAINT: ensure tests are included in wheels

[rgommers]

Also test install via sdist and wheel on TravisCI. Closes gh-280.

[rgommers]

A test unrelated to this PR is failing:

FAIL: test_deprecations.test_MODES_attributes_usage_deprecation
....
AssertionError: No warning raised when calling dwt

[rgommers]

I can't reproduce the failure locally, but it's consistent on TravisCI it looks like. I'm tempted to just delete that test. We're removing that deprecated code anyway before the next release.

[grlee77]

the same error is also present in python 2.7 on Appveyor, but I do not see it locally when using 2.7.

I would be find with removing that test.

[grlee77]

Nice to see tests for wheel and sdist builds were added on Travis!

I see you have included the files via package_data rather than adding an __init__.py in the test folders. I don't see a problem with doing it that way, but out of curiosity, do you recall the drawbacks of the __init__.py approach?

[rgommers]

Failing test removed, seems happy now.

[rgommers]

do you recall the drawbacks of the __init__.py approach?

One is that tests will start to show up when tab-completing. There was something more subtle as well, but can't remember.

[codecov-io]

Codecov Report

Merging #292 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #292   +/-   ##
=======================================
  Coverage   86.26%   86.26%           
=======================================
  Files          21       21           
  Lines        3086     3086           
  Branches      532      532           
=======================================
  Hits         2662     2662           
- Misses        371      372    +1     
+ Partials       53       52    -1

Impacted Files	Coverage Δ
pywt/_wavelet_packets.py	78.12% <0%> (ø)	✅

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[grlee77]

Thanks @rgommers!