Pydantic

* support dataclasses.InitVar, [592](https://github.com/pydantic/pydantic/pull/592) by pfrederiks
* Updated documentation to elucidate the usage of `Union` when defining multiple types under an attribute's
annotation and showcase how the type-order can affect marshalling of provided values, [594](https://github.com/pydantic/pydantic/pull/594) by somada141
* add `conlist` type, [583](https://github.com/pydantic/pydantic/pull/583) by hmvp
* add support for generics, [595](https://github.com/pydantic/pydantic/pull/595) by dmontagu

* fix support for JSON Schema generation when using models with circular references in Python 3.7, [572](https://github.com/pydantic/pydantic/pull/572) by tiangolo
* support `__post_init_post_parse__` on dataclasses, [567](https://github.com/pydantic/pydantic/pull/567) by sevaho
* allow dumping dataclasses to JSON, [575](https://github.com/pydantic/pydantic/pull/575) by samuelcolvin and DanielOberg
* ORM mode, [562](https://github.com/pydantic/pydantic/pull/562) by samuelcolvin
* fix `pydantic.compiled` on ipython, [573](https://github.com/pydantic/pydantic/pull/573) by dmontagu and samuelcolvin
* add `StrictBool` type, [579](https://github.com/pydantic/pydantic/pull/579) by cazgp

* **breaking change** `_pydantic_post_init` to execute dataclass' original `__post_init__` before
validation, [560](https://github.com/pydantic/pydantic/pull/560) by HeavenVolkoff
* fix handling of generic types without specified parameters, [550](https://github.com/pydantic/pydantic/pull/550) by dmontagu
* **breaking change** (maybe): this is the first release compiled with **cython**, see the docs and please
submit an issue if you run into problems

* fix JSON Schema for `list`, `tuple`, and `set`, [540](https://github.com/pydantic/pydantic/pull/540) by tiangolo
* compiling with cython, `manylinux` binaries, some other performance improvements, [548](https://github.com/pydantic/pydantic/pull/548) by samuelcolvin

* fix to schema generation for `IPvAnyAddress`, `IPvAnyInterface`, `IPvAnyNetwork` [498](https://github.com/pydantic/pydantic/pull/498) by pilosus
* fix variable length tuples support, [495](https://github.com/pydantic/pydantic/pull/495) by pilosus
* fix return type hint for `create_model`, [526](https://github.com/pydantic/pydantic/pull/526) by dmontagu
* **Breaking Change:** fix `.dict(skip_keys=True)` skipping values set via alias (this involves changing
`validate_model()` to always returns `Tuple[Dict[str, Any], Set[str], Optional[ValidationError]]`), [517](https://github.com/pydantic/pydantic/pull/517) by sommd
* fix to schema generation for `IPv4Address`, `IPv6Address`, `IPv4Interface`,
`IPv6Interface`, `IPv4Network`, `IPv6Network` [532](https://github.com/pydantic/pydantic/pull/532) by euri10
* add `Color` type, [504](https://github.com/pydantic/pydantic/pull/504) by pilosus and samuelcolvin

* Improve documentation on self-referencing models and annotations, [487](https://github.com/pydantic/pydantic/pull/487) by theenglishway
* fix `.dict()` with extra keys, [490](https://github.com/pydantic/pydantic/pull/490) by JaewonKim
* support `const` keyword in `Schema`, [434](https://github.com/pydantic/pydantic/pull/434) by Sean1708