Fix spec warnings

[axfcampos]

Hi all,

When running specs with warnings on, grape outputs a lot of warnings.

This PR attempts to fix all of them.

With regards to the warnings: warning: instance variable @disable_warnings not initialized, by the hashie gem, I have opened a PR there to fix those: hashie/hashie#416

[dblock]

Interesting. This feels like a workaround rather than a fix. Why wouldn't something like @status for example not be defined?

[axfcampos]

Hi @dblock the warnings occur because @status is in fact not defined when it is accessed. This may only happen in the specs...

I did not look into implementation details, my objective was to clear three warnings that were showing in my projects specs, but since I'm here might as well fix them all 😄

Having warnings not suppressed has saved me from some bugs in the past, but it comes with the caveat of having to fix them if we want a sane output when running tests 😛

Would you like me to change something on the PR?

[dblock]

Yes, lets have this discussion in hashie/hashie#416 first? Same problem but fewer changes.

[namusyaka]

Thanks for your contribution.
I'd like to postpone this until after 1.0.0 release is made.

[dblock]

I want to revive this. I think a fix that says if defined(:@foobar) is not what we want. Lets initialize variables where needed instead? What do you think @axfcampos?