Adds Ark 0.4 which Maven 1.1.1 depends on

Without it I was getting:
```
Berkshelf::NoSolutionError: Unable to satisfy constraints on package ark due to solution constraint (maven = 1.1.1). Solution constraints that may result in a constraint on ark: [(ark = 0.3.1)], [(maven = 1.1.1) -> (ark ~> 0.4)]
Demand that cannot be met: (maven = 1.1.1)
Artifacts for which there are conflicting dependencies: ark = 0.3.1 -> []Unable to find a solution for demands: ark (0.3.1), docker (0.34.1), maven (1.1.1), mesos (0.1.0)
```
Update Berksfile
Merge pull request #16 from thebyrd/patch-1

Adds Ark 0.4 which Maven 1.1.1 depends on