v0.11.0

This release brings little changes but there are two reasons why it is released as major version:

1. To follow reference implementation versions (it matches 0.11.x series of graphql-js)
2. It may break existing applications because scalar input coercion rules are stricter now:
   
   In previous versions sloppy client input could leak through with unexpected results.
   For example string "false" accidentally sent in variables was converted to boolean true
   and passed to field arguments. In the new version, such input will produce an error
   (which is a spec-compliant behavior).

Improvements:

• Stricter input coercion (see #171)
• Types built with BuildSchema now have reference to AST node with corresponding AST definition (in $astNode property)
• Account for query offset for error locations (e.g. when query is stored in .graphql file)