Be able to chain injection steps and adds SteppedRampsInjection
introduce the split(x users).into(...).speratedBy(...) injection DSL
Merge @excilys/master into @nremond/injection_stream
DSL shortcut for split().into().separatedBy(d:FiniteDuration)
Merge pull request #1036 from nremond/injection_stream

Be able to chain injection steps and adds SteppedRampsInjection