travis: Test whether migrations are consistent with models.

This should automatically catch mistakes where someone updates the
database models but forgets to generate migrations afterwards.

tools/test-all

@@ -16,6 +16,7 @@ function run {
 
 run ./tools/clean-repo
 run ./tools/lint-all
+run ./tools/test-migrations
 run ./tools/test-js-with-node
 run ./tools/test-backend
 run ./tools/test-js-with-casper

tools/test-migrations

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -e
+echo 'Testing whether migrations are consistent with models'
+if ./manage.py makemigrations -e --dry-run; then
+    echo
+    echo 'ERROR: Migrations are not consistent with models!  Fix with `./manage.py makemigrations`.'
+    echo
+else
+    echo "Success!  Migrations are consistent with models."
+fi

tools/travis/backend

@@ -6,3 +6,4 @@ export PATH=$PATH:/srv/zulip-venv/bin
 ./tools/lint-all
 ./tools/test-backend
 ./tools/test-management
+./tools/test-migrations