[MRG] turn warnings into error in the doc generation

[lesteve]

• ignore "nonlocal image URI found"
• add doc generation in one of the Travis build

I had to fix a few warnings before the release and it would be great to do this incrementally on each PR instead.

[lesteve]

This is just to make sure that the CIs pass and that Travis does generate the doc. I'll merge this when this is the case.

[codecov]

Codecov Report

Merging #504 into master will increase coverage by 1.86%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #504      +/-   ##
==========================================
+ Coverage   91.05%   92.92%   +1.86%     
==========================================
  Files          37       37              
  Lines        4764     4764              
==========================================
+ Hits         4338     4427      +89     
+ Misses        426      337      -89

Impacted Files	Coverage Δ
joblib/logger.py	85.52% <0%> (+1.31%)	✅
joblib/test/test_parallel.py	92.83% <0%> (+1.85%)	✅
joblib/disk.py	80.39% <0%> (+1.96%)	✅
joblib/test/test_numpy_pickle.py	99.04% <0%> (+2.68%)	✅
joblib/backports.py	85.41% <0%> (+4.16%)	✅
joblib/pool.py	90.32% <0%> (+7.25%)	✅
joblib/test/test_pool.py	99.59% <0%> (+7.72%)	✅
joblib/test/common.py	75% <0%> (+11.53%)	✅
joblib/test/test_hashing.py	98.32% <0%> (+11.73%)	✅

---

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 6ffbb87...99ea07a. Read the comment docs.

[GaelVaroquaux]

Merging #504 into master will increase coverage by 2.62%. + Coverage 91.05% 93.68% +2.62%

Congratulations!

[lesteve]

Congratulations!

Not 100% sure what the congratulation is about. If this is about the coverage increase, I think that this is very likely bogus.

[GaelVaroquaux]

Not 100% sure what the congratulation is about. If this is about the coverage increase, I think that this is very likely bogus.

:(