Create a new app to hold GenerateSqlSchemaCommand (#409)

* Create a new app to hold GenerateSqlSchemaCommand

GenerateSqlSchemaCommand starts postgresql using testcontainer.
This makes junit etc a runtime dependency, allowing them to get
into release artifacts.

By moving this command to a separate tool, we can remove junit
etc as compile/runtime dependency.

dependencies.gradle

@@ -138,6 +138,7 @@ ext {
       'org.testcontainers:selenium:1.12.1',
       'org.testcontainers:testcontainers:1.12.1',
       'org.yaml:snakeyaml:1.17',
+      'pl.pragmatists:JUnitParams:1.1.1',
       'xerces:xmlParserAPIs:2.6.2',
       'xpp3:xpp3:1.1.4c'
     ]