Issue with mypy versions containing more than one '.'

[anjz]

Hi there,
I've noticed that the following conversion is problematic when version has more than 1 decimal point. For example with version 1.0.0. That string can't be converted to float.

jsonschema-typed/jsonschema_typed/plugin.py

Line 583 in 54d2f8c

if float(version) < 0.7:

Maybe using a package like semver could be handy here.

Thanks