chore: Use Parity 2.7.2 (#588)

* bump

* remove comment
5 jobs for master in 16 minutes and 43 seconds
Status Job ID Name Coverage
  Test
passed #378790
linux-docker
linux-test

00:02:36

 
  Build
passed #378791
linux-docker
linux-build

00:07:23

passed #378996
darwin-shell
osx-build

00:06:43

passed #378793
linux-docker
win-build

00:04:56

passed #378792
darwin-shell
osx-build

00:06:52