version bump

tomdoc, deprecate operations on zipcode integers, check for us states…

… before converting to zipcodes, return arrays in in all #to_zip methods

performance improvements

return nil or an empty array if there are no results. closes #4

[v0.6.0] fix nasty bug for zips with leading zeros. get an area code …

…from a string or integer

bump version

correct version

bump version number

break out classes by type

[v0.2.0] add support to convert region to area code. lose any regex m…

…atching.