Modernize ruby/bundler versions

[drusepth]

I'm not sure what Ruby version this broke on, but trying to run it on 2.7.2 gave a syntax error for the fixed regex (because it treated - within the regex as a range identifier, instead of the literal -).

This PR moves the - to the end of the char-class (just swapping positions with the _ character next to it) and also updates ruby/bundler to more modern versions.

This was the error I got when trying to use the gem in a modern project:

Syntax Error: unmatched range specifier in char-class: 
                  /((([A-Za-z]{3,9}:(?:\\/\\/)?)(?:[-;:&=\\+\\$,\\w]+@)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\\+\\$,\\w]+@)[A-Za-z0-9.-]+)((?:\\/[\\+~%\\/.\\w-_]*)?\\??(?:[-\\+=&;%@.\\w_]*)#?(?:[\\w]*))?)/ (SyntaxError)

After this fix, tests now pass and things seem to work as expected.