Use dzil test --release instead of xtest/test
remove superflous \n
Synchronise git subtree maint-travis-ci
Factor out constants to use GraphViz2::Abstract::Util::Constants
Update changes
v0.002000

 - Factor out constants into GraphViz2::Abstract::Util::Constants

 [Dependencies::Stats]
 - Dependencies changed, see Changes.deps{,.all,.dev} for details
 - develop: +2 ↑1 -2
 - runtime: +1 -1