Check bcbio validation runs

Compare validation outputs from bcbio against existing truth sets. Designed for the GA4GH-DREAM Tool Execution Challenge, this provides a Docker container and CWL wrapper for verifying that a bcbio validation is correct. bcbio itself runs alignment, variantcalling and validation against known truth sets from Genome in a Bottle reporting sensitivity and specificity for samples and methods. This look takes these outputs and ensures they match previous results.