Stable

This library has been stable for a while, so it's time to make it official: v1.0.0.

These changes have landed in the past few days:

• Remove support for Python 2 #75 (and 3.4 and 3.5, for good measure)
• Reorganize tests and switch to pytest #74 and #47
• Use handler.detect instead of that weird global dictionary #48
• Add a handler.format method to customize output #49
• Add a directory of examples to show ways to solve problems people have raised #72

All that said, the API hasn't really changed, except for dropping Python 2 support. This is more a promise that it won't change (at least until v2).

Everything should be a little tighter and more predictable now, and testing should be a little easier and better organized.