added HRNet+OCR, minor changes

[valhassan]

Thank you for submitting your PR and helping us with GDL.
Please read the template below, fill it out as appropriate, and make additional changes to your code as needed.
Please feel free to submit your PR even if it doesn't satisfy all of the requirements below.
If you need assistance or review from a maintainer, add the label Status: Help Needed or Status: Review Needed respectively.
After review, a maintainer will add the label Status: Revision Needed if further work is required for the PR to be merged.

Description

HRNet+OCR model architecture.
Fixes #543

Type of change

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other

How Has This Been Tested?

If the added changes are already cover by tests, skip that section.
Otherwise, please describe tests that you added to the pytest codebase (if applicable).
minor tweak to test_models.py to accommodate auxiliary output

Screenshots (if applicable):

Checklist:

If you're unsure about any of these, don't hesitate to ask. We're here to help!

• My code follows the code style of this project
• I have performed a self-review of my own code
• My PR has a descriptive title
• My code follows PEP8 (most of it)
• My code have the proper documentation in the code
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new errors
• My code is covered by the existing tests (if applicable)
• My code includes tests that show that my feature works
• My PR passes Travis CI tests

If your PR does not fulfill all of the requirements in the checklist above, that's OK! If you need help, @-mention a maintainer and/or add the Status: Help Needed label.

[CharlesAuthier]

can you add the doc for this please

[valhassan]

@CharlesAuthier do you mean the architecture paper?

[CharlesAuthier]

yeah with a little resume in the https://github.com/NRCan/geo-deep-learning/blob/develop/docs/source/model.rst doc