Added the priciples, sub principles and the groups.

test/models/subprincipalitem_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class SubprincipalitemTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/models/subprincipalitemgroup_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class SubprincipalitemgroupTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/models/subprinciple_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class SubprincipleTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end