v1.2.0

Enhancements:

• Run tests against Centos 7. (#359)

Maintenance:

• Run Travis CI on maintenance and tagged branches. (#352)
• Only test branch builds on Appveyor for master and maintenance branches. (#364)

Big fixes:

• Add the license to the manifest. (#354)
• Fix platform detection on Centos 7. (#161)
• Fix error when '$' is in the Python runtime prefix. (#309)