Release 3.1.1

Release 3.1.0

Release 3.0.3

Bump version number

Remove an example, add a test for multiple handler registration

The `simple` example was a bit too simple with no easy way to shut down
the executable. I feel that the readme example does a better job
explaining this crate anyway, so removed the `simple` example.

Bump version number to 3.0.1

Bump version number, add contributors to authors list

Add a feature flag `termination`

This feature flag allows the users to set the handler for SIGTERM as well as SIGINT.
The flag only affects Linux at the moment.

Bump major version number

Because of backwards-incompatible changes

Bump version number

Add documentation to README