v0.7.4

ChainRulesCore v0.7.4

Diff since v0.7.1

Closed issues:

• Make good error message for can't construct only show in DebugMode (for performance reasons) (#82)
• @allocated and 1.4 (#141)

Merged pull requests:

• Export AbstractThunk (#135) (@nickrobinson251)
• Add Debug Mode (#136) (@oxinabox)
• Document why we have a many-many relationship between differential types and primal types (#138) (@oxinabox)
• [WIP] Fix allocations on 1.4 (#142) (@willtebbutt)
• Fix indenting in composite tests (#145) (@oxinabox)
• define keys(::Composite) (#148) (@simeonschaub)