Stryker4s v0.5.1

Bugfixes

• Fix glob pattern for collection files to be mutated (#219)
  • This pattern takes into accounts located in the root
    of the Scala source directory as well, not just those
    in subdirectories.

Other changes

• Update grizzled-slf4j to 1.3.4 (#216)
• Update mockito-scala-scalatest to 1.5.9 (#217)