`ifNotFloat` has different behavior than `ifNotInt`

[jaredramirez]

The function ifNotFloat will error if the subject is a float, whereas ifNotInt will error if the subject is not an int. I believe the behavior of ifNotInt is correct. In the definition of isNotFloat, ifTrue, should be ifFalse.

The current definition:

ifNotFloat : (subject -> String) -> error -> Validator error subject
ifNotFloat subjectToString error =
    ifTrue (\subject -> isFloat (subjectToString subject)) error

The correct definition:

ifNotFloat : (subject -> String) -> error -> Validator error subject
ifNotFloat subjectToString error =
    ifFalse (\subject -> isFloat (subjectToString subject)) error

Note:
The definition of ifNotFloat and ifNotInt also differ in the second argument as well. ifNotInt takes a function with the invalid int, whereas ifNotFloat takes just the error. Any changes to ifNotFloat should probably also reconcile the definitions to be the same.