allow token_owner to be passed to the hidden proc for parameters as well

[urkle]

This allows the same functionality that is offered by the route-level hidden procs.

[coveralls]

Coverage increased (+0.002%) to 99.671% when pulling 3b76755 on urkle:feat-token_owner-for-params-parser-hidden into 11d29c4 on ruby-grape:master.

[coveralls]

Coverage increased (+0.002%) to 99.671% when pulling 3b76755 on urkle:feat-token_owner-for-params-parser-hidden into 11d29c4 on ruby-grape:master.

[coveralls]

Coverage decreased (-0.1%) to 99.56% when pulling 1994b05 on urkle:feat-token_owner-for-params-parser-hidden into 11d29c4 on ruby-grape:master.

[coveralls]

Coverage increased (+0.002%) to 99.671% when pulling 3b76755 on urkle:feat-token_owner-for-params-parser-hidden into 11d29c4 on ruby-grape:master.

[coveralls]

Coverage increased (+0.002%) to 99.671% when pulling 3b76755 on urkle:feat-token_owner-for-params-parser-hidden into 11d29c4 on ruby-grape:master.

[grape-bot]

	1 Error
🚫	One of the lines below found in CHANGELOG.md doesn’t match the expected format. Please make it look like the other lines, pay attention to periods and spaces.

* [#749](https://github.com/ruby-grape/grape-swagger/pull/749) Drop support for Ruby 2.3 and below - [@LeFnord](https://github.com/LeFnord).

Generated by 🚫 danger

[LeFnord]

thanks @urkle … will be mörged