Last Python 2-compatible release

This is the last commit before backward-incompatible OpenMDAO 3 features are used. OM 3 doesn't support Python 2 anymore and Python 2 testing will be dropped.

OpenConcept 0.0.1

Initial OpenConcept release.

What's Changed

• Fix python 2 division issue in the Simpson integraton component by @bbrelje in #4
• First big batch of component tests and scipy 1.1.0 fix by @bbrelje in #5
• Formatting updates by @bbrelje in #6
• Enable automatic documentation by @bbrelje in #7
• More docs updates by @bbrelje in #8

Full Changelog: https://github.com/mdolab/openconcept/commits/v0.0.1