Feature
(#485) Da steve101 tree reduce
(#1103) Add running one testcase to mill
(#1176) Add requirements to Queue class
Improve error reporting on invalid Queue sizes
(#1177) Fix Queue.apply for size 0 in chisel3._ code
(#1179) Bump Scala to 2.12.10
(#1181) Updated to sbt 1.3.0
