fixes for optional casting

add support for immutable collections

improved generation for type parameters

upgrade swiftpoet

add jitpack config

remove circle webhook

Merge pull request icerockdev#66 from icerockdev/develop

Release 0.6.1

fix publication of runtime

Merge pull request icerockdev#41 from icerockdev/develop

Release 0.5.0

Merge pull request icerockdev#38 from icerockdev/develop

Release 0.4.0