Update readme.
Merge pull request #16 from dhui/readme

Update readme.
Link to our blog post.
Merge pull request #17 from dhui/readme

Link to our blog post.
Add tests for comparisons
Raise warnings when comparing to non-enum values

This should help when migrating to enums; the warnings don't stop
execution, but they will get logged as exceptions.
Merge pull request #18 from akshayjshah/warn

Raise warnings on comparisons to other types
Forgot to add to changelog and bump version
Merge pull request #19 from akshayjshah/warn

Forgot to add to changelog and bump version
Better warnings for cross-type comparisons

Set the stacklevel when warning so there's a better chance of warning
about the correct caller. Also log a complete stacktrace.
Use a named logger
Merge pull request #21 from akshayjshah/warn

Better warnings for cross-type comparisons