Relax Cowboy dependecy

[Łukasz Jan Niemier]

Or even remove it as whole project doesn't need exactly cowboy and Plug should manage that. If removal is not an option then relax it to ~> 1.0 or >= 1

[Michael Schaefermeyer]

I have no idea why I have the cowboy dep in there but it doesn't make any sense. I'll delete it and release a new minor version as dependencies have changed.

Thanks for the heads-up.

[Michael Schaefermeyer]

v1.2.0 was released