support for Grape 0.10 with refactored settings

[mmclead]

This pull request enables support for Grape 0.10 since they refactored the way settings are set and retrieved. Also added Appraisals gem to test both versions locally and on travis-CI.

If you can find a prettier way of dealing with this please comment or update.

Can run specs against Grape 0.10 and 0.9 with:

bundle exec appraisal rspec spec

[davidcelis]

Thanks for the PR! This solution is good, but I'm not sure if I want to deal with divergent code paths in a single version... I wonder if it would be a better idea to simply change the implementation of Grape and bump api-pagination's major version since it's a breaking change? I can maintain a branch with the current major version, leave Grape's implementation, and continue to merge in bug fixes as they come in.

Also, looking over Grape's changes to settings, it seems like there are a lot of options now... namespace_inheritable, namespace_setting, namespace_stackable, route_setting... My guess is that the type of setting we actually want is route_setting as we're setting pagination info on a single endpoint as opposed to an entire namespace. Would you agree?

[mmclead]

It does look like route_setting is the more appropriate setting for this. Moving a major version makes sense to me if you don't want to have the version checking inside the code. Easier to maintain that way too.
I'll update my PR to use route_setting and set the .gemspec to specify grape >= 0.10.1.
I'll leave setting the version of this gem to you after merging.

[davidcelis]

Thanks a bunch!

[davidcelis]

Actually should this be '>= 0.10.0'? Or did the breaking change come in 0.10.1?

[mmclead]

0.10.0. good catch

[coveralls]

Changes Unknown when pulling 34879e8 on mmclead:master into * on davidcelis:master*.