Changelog for elm-street-0.1.0.2

Changelog

elm-street uses PVP Versioning. The changelog is available on GitHub.

#89: Regulate parenthesis on complicated types in encoder, decoder and type generation.

#80: Important: All encoders for constructors with fields now have tag due to aeson decoder on Haskell side.

Migration guide 1: Rename fields that will have tag name on the Elm side.

Migration guide 2: If you have manual ToJSON instances that communicate with Elm via generated decoders, you need to add tag field with the constructor name:
```
data User = User { ... }

instance ToJSON User where
    toJSON = [ "tag" .= ("User" :: Text), ... ]
```
#71: Breaking change: Remove overlapping instance for String.

Migration guide: Use Text instead of String.
#70: Use qualified imports of generated types and function in Elm generated files.
#74: Fix unit type typeRef encoder and decoder printers.
#72: Use consistent encoders and decoders for unary constructors.
#79: Implement cross-language golden tests.
#76: Support GHC-8.6.5. Use common stanzas.
#86: Refactor Elm.Print module and split into multiple smaller modules.
#73: Clarify the restriction with reserved words in documentation.
#90 Support converting 3-tuples.
#6: Test generated Elm code on CI.