Add DGIWG and NSG test suites to Docker project

[dstenger]

Working branches already exist:

• https://github.com/lat-lon/teamengine-docker/tree/addDGIWGTestSuites
• https://github.com/lat-lon/teamengine-docker/tree/addNSGTestSuites

[dstenger]

All missing test suites were added:

• https://github.com/opengeospatial/teamengine-docker/pull/14
• https://github.com/opengeospatial/teamengine-docker/pull/15