ENH: Added test using google test framework.
ENH: Added test using google test framework.

Went quite smoothly following Dan's instructions.

blowekamp/SimpleITK,SimpleITK/SimpleITK,SimpleITK/SimpleITK,kaspermarstal/SimpleElastix,hendradarwin/SimpleITK,hendradarwin/SimpleITK,SimpleITK/SimpleITK,SimpleITK/SimpleITK,kaspermarstal/SimpleElastix,SimpleITK/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,richardbeare/SimpleITK,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,hendradarwin/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,blowekamp/SimpleITK,kaspermarstal/SimpleElastix,blowekamp/SimpleITK,SimpleITK/SimpleITK,blowekamp/SimpleITK,blowekamp/SimpleITK,blowekamp/SimpleITK,InsightSoftwareConsortium/SimpleITK,SimpleITK/SimpleITK,richardbeare/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,blowekamp/SimpleITK,InsightSoftwareConsortium/SimpleITK,hendradarwin/SimpleITK,hendradarwin/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,InsightSoftwareConsortium/SimpleITK,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,hendradarwin/SimpleITK,SimpleITK/SimpleITK,richardbeare/SimpleITK,hendradarwin/SimpleITK,blowekamp/SimpleITK,hendradarwin/SimpleITK