Remove UserAgentParser.parse

[toolmantim]

It causes unexpected performance problems (#4 #5 #13). The simpler UserAgentParser.new.parse should be less confusing.

A backwards incompatible change for v3.

[wallin]

@toolmantim Is this still relevant?

[soulcutter]

@wallin This is still relevant. We hit this footgun using the class method in a rails request - loading the yaml and compiling the regexes on every request. This added about 40-50ms per-request, which is quite unexpected and one of those things that's really easy to miss when you first introduce using this gem - though I appreciate the readme does attempt to address it.

If the docs clearly stated "Expect this method to take 50ms" I suspect nobody would use it. I support this issue.

[AxelTheGerman]

First step could be to add a deprecation warning maybe? That could already educate and also help transition.