Update README

Merge pull request #352 from eikek/update/sbt-scalafix-0.12.0

Update sbt-scalafix to 0.12.0

Merge pull request #356 from eikek/fix/353-unspecific-number

Support `number` without `format`

Merge pull request #332 from eikek/arbitrary-json

Allow arbitrary json values for code generation

Merge pull request #286 from er1c/trait-gen

Add support for generating scala traits

Merge pull request #164 from eikek/array-typedef

Array typedef

Merge pull request #115 from eikek/elm-optional-fields

Allow optional fields to be missing in elm decoder

Merge pull request #99 from mpapillon/fix-oneof-imports

Add missing imports for sub-schemas

Merge pull request #97 from eikek/remove-java

Remove support for java

Releasing 0.7.1