v1.4.2.7: DateType + EnumType changes, Updates for October specs

Despite being a minor update this version might require you to change a few things in your code.

1. DateTimeType and DateTimeTzType types are now working properly and parsing your input string into the \DateTime object in PHP. Also you can specify the exact format of the DateType when creating a field in constructor (for examplenew DateTimeType("m/d/Y H:ia")) .
2. EnumType now can return null values as it is in the official JS library and properly use name and value if they are not equal (e.g. {value: 1, name: "ACTIVE"}
3. All scalar types consider null values as valid values