Paramtools

- Display the bad value in all error messages. Previously, the bad value was not displayed in type error messages.
- Validation errors are raised via the `paramtools.ValidationError` class instead of `marshmallow.ValidationError`
- A bug that did not allow array parameters to use choice validation was resolved. Now, ParamTools checks that each element of the "value" array is in the choices list.
- Automated testing is set up.
- [Pre-commit][1] is used to [Black][2] changed code.

[1]: https://pre-commit.com/
[2]: https://github.com/ambv/black

This is the first release candidate for the 0.2.0 release:
- Display the bad value in all error messages. Previously, the bad value was not displayed in type error messages.
- Validation errors are raised via the `paramtools.ValidationError` class instead of `marshmallow.ValidationError`
- A bug that did not allow array parameters to use choice validation was resolved. Now, ParamTools checks that each element of the "value" array is in the choices list.
- Automated testing is set up.
- [Pre-commit][1] is used to [Black][2] changed code.

[1]: https://pre-commit.com/
[2]: https://github.com/ambv/black

Features:
- Use 'title' instead of 'long_name'.
- Add `to_array` and `from_array` to convert data from the Value object structure to an array structure.
- Add Order object to the spec. This is necessary for the first implementation of the array conversion methods.
- Revamp the docs to follow the Mozilla WOT API spec structure.
- Add automating testing with Travis CI.