Fix order of mounts with overrides

[adie]

The problem is that grape executes endpoints in the order of definition (like defined first - matched first), but documentation was showing information from the last defined endpoints.
Not sure if it's issue with the grape itself, but I think grape-swagger should be consistent with current state of grape gem.

[coveralls]

Coverage remained the same at 97.644% when pulling 75117e6 on Fuseit:order-of-mount-overrides into e9d9447 on ruby-grape:master.

[LeFnord]

thanks @adie … think it isn't really a 'problem' cause the documentation itself is a JSON and the the path section is a kind of a hash, so it has no order 😉 … but yeah, why not

[coveralls]

Coverage remained the same at 97.316% when pulling 0304878 on Fuseit:order-of-mount-overrides into 7d871ae on ruby-grape:master.