Add Travis configuration file
Adds the summarize_genotypes command described in #172 (closes #172). This command gives basic stats on a collection of ADAMGenotype records. Also adds methods to compute the type of a variant (SNV, insertion, deletion, etc.) in RichADAMVariant, which closes #174, and cleans up the no longer used VariantType enum in adam.avdl.
Merge pull request #187 from hammerlab/variant-stats-squashed

Add summarize_genotypes command
Update the SCM info for Jenkins release plugin
[maven-release-plugin] prepare release adam-parent-0.7.2
[maven-release-plugin] prepare for next development iteration
Merge branch 'master' of https://github.com/bigdatagenomics/adam into ref-id-to-name

Conflicts:
	adam-format/src/main/resources/avro/adam.avdl
Further refactoring of Sequence Dictionary to support ref-id-to-ref-name change