v0.1.3 release

[kandersolar]

• [x] Closes #175
• ~[ ] Added tests to cover all new or modified code.~
• ~[ ] Clearly documented all new API functions with PEP257 and numpydoc compliant docstrings.~
• ~[ ] Added new API functions to docs/api.rst.~
• ~[ ] Non-API functions clearly documented with docstrings or comments as necessary.~
• [x] Adds description and name entries in the appropriate "what's new" file in docs/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• [x] Pull request is nearly complete and ready for detailed review.
• [x] Maintainer: Appropriate GitHub Labels and Milestone are assigned to the Pull Request and linked Issue.

Keeping as draft for now in the hopes of wrapping up #167 first.

[kandersolar]

Rather than rushing #167 I'm inclined to push it to 0.1.4, since as @wholmgren often points out there's no reason we have to wait so long between releases.

@cwhanse @kperrynrel any final thoughts here? If no objections I'll proceed with merging and tagging.

[cwhanse]

@kanderso-nrel I say send it