Created by: gracewashere
Problem:
File paths within the lib folder have inconsistent pluralization.
According to ruby convention, each class should be stored in a file
where the parent directories correspond to the namespaces of the class.
For us, our Administrate::Field classes
are stored in administrate/fields.
The incorrect pluralization breaks Ruby's convention.
Solution:
Move lib/administrate/fields -> lib/administrate/field.