Fix version comparison of Werkzeug

[mtsgrd]

The existing comparison breaks flask_limiter when Werkzeug==0.10 is installed.

[coveralls]

Coverage remained the same at 100.0% when pulling 8f5fdcb on YoApp:master into a2eb928 on alisaifee:master.

[alisaifee]

Thanks @mtsgrd

[g-p-g]

Wouldn't it be better to use pkg_resources.parse_version(...) so it avoids an unnecessary import?

[mtsgrd]

@g-p-g you're right. It could look like this:

pkg_resources.get_distribution("werkzeug").parsed_version < pkg_resources.parse_version("0.9")