Add a generate_sql_schema command (#230)

* Add a generate_schema  command

Add a generate_schema command to nomulus tool and add the necessary
instrumentation to EppResource and DomainBase to allow us to generate a
proof-of-concept schema for DomainBase.

* Added forgotten command description

* Revert "Added forgotten command description"

This reverts commit 09326cb8ac.
(checked in the wrong file)

* Added fixes requested during review

* Add a todo to start postgresql container

Add a todo to start a postgresql container from generate_sql_command.

config/dependency-license/allowed_licenses.json

@@ -75,6 +75,9 @@
     {
       "moduleLicense": "BSD style"
     },
+    {
+      "moduleLicense": "BSD-2-Clause"
+    },
     {
       "moduleLicense": "New BSD License"
     },
@@ -84,6 +87,9 @@
     {
       "moduleLicense": "The BSD License"
     },
+    {
+      "moduleLicense": "The PostgreSQL License"
+    },
     {
       "moduleLicense": "CC0 1.0 Universal License"
     },
@@ -105,6 +111,9 @@
     {
       "moduleLicense": "\\n                Dual license consisting of the CDDL v1.1 and GPL v2\\n            "
     },
+    {
+      "moduleLicense": "Eclipse Distribution License v. 1.0"
+    },
     {
       "moduleLicense": "Eclipse Public License - Version 1.0"
     },
@@ -135,6 +144,9 @@
     {
       "moduleLicense": "GNU Lesser Public License"
     },
+    {
+      "moduleLicense": "GNU Library General Public License v2.1 or later"
+    },
     {
       "moduleLicense": "The Go license"
     },