v1.2.1

ControlSystems v1.2.1

Diff since v1.2.0

Merged pull requests:

• Use freqresp instead of functor (#724) (@baggepinnen)
• Don't treat Q's like easily readable arrays (#725) (@dkarrasch)
• increase timeout (#726) (@baggepinnen)
• reduce allocations and compile time in feedback (#727) (@baggepinnen)