Release v1.3.1

Changes for v1.3.1:

• Revamped the handling of data type declarations in col_type_is() to always accurately normalize data type representations, whether using aliases, such as varchar for character varying, or more complicated types that failed to work in v1.3.0, such as interval second(0). This is done by delegating the parsing of the type declaration to a core PostgresSQL function. Many thanks to Erik Wienhold for the report and for ultimately uncovering and implementing an SQL interface to the parseTypeString() core function (#315).
• Removed the documentation for pg_typeof(), which was removed from pgTAP when support for PostgreSQL 8.3 was dropped, since the same function has been available in the PostgreSQL core since then.
• Improved the support for type name aliases to the following functions:
  • has_cast()
  • hasnt_cast()
  • cast_context_is()
  • domain_type_is()
  • domain_type_isnt()
  • has_operator()
  • hasnt_operator()
• Added the has_pk( :schema, :table ) variant, which requires that :table be cast to name to avoid confusion with the has_pk( :schema, :description ) variant. Thanks to Adrian Klaver for the report (#287)!