fix(config): change the cpu limit to string instead of int

[kmala]

cpu limit has to be string and int. TestCase:

deis limits:set -c cmd=125m
git push deis master

this will fail before the fix with error Error running git receive hook [getting app config for classy-teamwork (json: cannot unmarshal string into Go value of type int)] and should pass after the fix

[Joshua-Anderson]

I believe that this is fixed in the controller SDK. Do we want to merge this or simply merge #402

[bacongobbler]

Let's go forward with #402 to fix this

[kmala]

yeah #402 should fix this. Closing this in favor of it.