add db_upgrade test

We have a database schema upgrade path, but so far nothing that verifies that
we don't break it. It almost seems like the user data weren't important to us!?

Add a db upgrade test:
- Create a db with an .sql dump taken from a db created with an old osmo-hlr,
  producing DB schema version 0.
- Run osmo-hlr --db-upgrade --db-check
- Verify that the upgrade exited successfully.
- Verify that restarting with the upgraded DB works.

If python tests are enabled, also:
- create a new database using the new osmo-hlr (just built).
- replay a VTY transcript to create subscribers as in the old snapshot.
- replay some sql modifications as done in the old snapshot.
- Get a list of sorted table names,
- a list of their sorted columns with all their properties,
- and dump the table contents in a column- and value-sorted way.
- Compare the resulting dumps and error if there are any diffs.
(This is how I found the difference in the imei column that was fixed in
I68a00014a3d603fcba8781470bc5285f78b538d0)

Change-Id: I0961bab0e17cfde5b030576c5bc243c2b51d9dc4
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4da8ab1..357fbac 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -3,6 +3,7 @@
 	gsup_server \
 	db \
 	gsup \
+	db_upgrade \
 	$(NULL)
 
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
@@ -44,6 +45,7 @@
 # don't run vty and ctrl tests concurrently so that the ports don't conflict
 	$(MAKE) vty-test
 	$(MAKE) ctrl-test
+	$(MAKE) db-upgrade-equivalence-test
 else
 python-tests:
 	echo "Not running python-based external tests (determined at configure-time)"
@@ -81,6 +83,9 @@
 	-rm -f $(CTRL_TEST_DB)
 	-rm $(CTRL_TEST_DB)-*
 
+db-upgrade-equivalence-test:
+	$(MAKE) -C db_upgrade upgrade-equivalence-test
+
 check-local: atconfig $(TESTSUITE)
 	$(SHELL) '$(TESTSUITE)' $(TESTSUITEFLAGS)
 	$(MAKE) $(AM_MAKEFLAGS) python-tests