broote v0.4.0

Renamed some args of 'runner'(#7)

Closes #7

This commit introduces incompatible changes that wont work with previous code.
Any code based on previous versions will need to change 'connect' to 'connector'.
'after_attempt' will need to be changed to 'after_connect'.

This will break 'webrute' first version since it expected major changes to happen at v1.0.0.