Remove unused constants

Author: jason-fox

lib/constants.js

@@ -23,9 +23,7 @@
  * Modified by: Daniel Calvo - ATOS Research & Innovation
  */
 
-const LOCATION_TYPE = 'geo:point';
 const LOCATION_DEFAULT = '0, 0';
-const DATETIME_TYPE = 'DateTime';
 const DATETIME_DEFAULT = '1970-01-01T00:00:00.000Z';
 const ATTRIBUTE_DEFAULT = ' ';