Go modules; don't panic

Enables Go modules.

Since years the master branch had a commit, that removes panics on misconfiguration, but instead makes the limiter a no-op when the requested bandwidth is zero or negative. This release includes that commit, so users can pull it.

Move default branch from master to main. The master branch still exists for now.

Patch release with micro changes

This release adds a few edge case tests. There are no functional changes, the main code is almost untouched.

Stable release

v1.0.0

typo