Merge pull request #10 from stevejameskent/milestone1

Implement the 'numeric' brij-spec support functions
Implement 'string' functions for cfpb/hmda-pilot#79
Fix typo in field name
add dataType to required fields
Validate a field is a number if the datatype is number
return a field name for the error message
Merge pull request #11 from doelleri/string-functions

Implement 'string' functions
Provide a more clear error message for field validation
Merge pull request #13 from stevejameskent/milestone1

Implement the 'formatting' brij-spec support functions
Merge pull request #12 from doelleri/validate-field-format

Validate field format in HMDA file