Remove unused task
Update Appraisal gemfiles
Add Cequel::Record::ClassMethods

Provides a hook for other libraries to extend Cequel::Record with class-level
functionality
Bump version
Update Appraisal gemfiles
Add generator for records
Add `[]` and `[]=` method for property access

Parity with ActiveRecord
Fallback when inferring model class

If requiring a model file doesn't cause any new constants to appear (e.g. if
something else has already loaded the file), try to infer the model class from
the file name.