Change to the Apache 2 licence

[thomasbird]

It is proposed to change the licence of this project from MIT to Apache 2.0.

To quote from exygy.com who compare the two:

The Apache license has a similar philosophy to the MIT, but uses more words. The wordiness creates greater specificity about contributors’ obligations, which might help in a dispute. But it also can be a turnoff — “Do I need to have my lawyer look at this?” comes up more with Apache than MIT. It works well for organizations or projects that are larger and managing more contributors, but don’t care about others commercializing the work. It also can help bring on board organizations that are more concerned about software patents or patent trolls.

I think the main gist is that it is very similar to the MIT licence, but lays the foundation to help deal with some situations that could crop up especially around patients.

What do people think about this proposed change?

[coveralls]

Coverage increased (+0.05%) to 95.968% when pulling 01f37ed on licence/apache into c1050ce on master.

[deanmalmgren]

This sounds reasonable to me. We first licensed this under MIT for simplicity, but if you have good reasons to have a different open source license that supports the use cases of this package, I'm supportive 👍 👍