Don't bump compat for equality specifiers

[mortenpi]

If you have e.g. Foo = "=1.2.3, CompatHelper will suggest Foo = "=1.2.3, 1 when e.g. 1.3 comes along. I don't think it should, since if you are using an equality specifier, you probably have a good reason not to allow newer versions.

Maybe tangentially related to #266?

[Octogonapus]

I think this is a duplicate of #250, which was fixed in #251, so this should be closed.

[mortenpi]

Oh, you need to set an argument to disable this. I never checked the main() docstring.

Then I would suggest making bump_compat_containing_equality_specifier=false the default, rather than true, although I know that would be a breaking change.