Use subproject instead of categories to exclude tests that need docker

gradle/any/testing.gradle

@@ -48,7 +48,14 @@ tasks.withType(Test).all {
       }
 
       if (skipDockerTests) {
-        excludeCategories 'ucar.unidata.util.test.category.NeedsDocker'
+        // dap4
+        exclude 'dap4/test/**'
+        // httpservices
+        exclude 'ucar/httpservices/**'
+        exclude 'ucar/nc2/util/net/**'
+        // opendap
+        exclude 'opendap/test/**'
+        exclude 'ucar/nc2/dods/**'
       }
     }
   }