v2.2

• Treat unknown properties as validation errors in validateToJSON (see #126);
• Add validateJSON and validateJSONWithPatternChecker to validate JSON Value against Schema without classes (see #126);
• Add more Schema helpers (see #126):
  • genericNameSchema — to give a custom schema Generic-based name;
  • genericDeclareNamedSchemaNewtype — to derive NamedSchema for newtypes;
  • declareSchemaBoundedEnumKeyMapping — to derive more specific Schema for maps with Bounded Enum keys;
• Add a few tests with invalid Schema.