Return the StepSummaryList from this call
Merge remote-tracking branch 'webfanatic/develop' into emr_step_summary
Fixed unit test for #1944 (StepSummaryList)
Added the M3 instance types.
Merge pull request #2012 from toastdriven/add-m3-instances

Added the M3 instance types.
Merge remote-tracking branch 'pasc/emr_step_summary' into develop
Fixes #2011.