Close and dispose test database setup connections

Without explicitly closing and disposing the connections can linger in a
non-deterministic fashion and cause intermittent "too many connection"
errors in the tests.

This is effectively a "backport" of change
I8badf2a3094f2d27d381bd178c6d579f2a5c5ffe in aodh, made here for
safety despite not seeing the problem regularly in the ceilometer
tests.

The -N 100 is removed from the setup-test-env so that we are using
whatever the postgresql default is, meaning that these tests will be
better at exposing errors that users may see.

Change-Id: I694d118ff8dc2b5c8be633121fa1037130fbe874

ceilometer/tests/db.py

@@ -92,6 +92,8 @@ class PgSQLManager(SQLManager):
         self._conn.execute(
             'CREATE DATABASE %s WITH TEMPLATE template0;' % self._db_name)
         self._conn.connection.set_isolation_level(1)
+        self._conn.close()
+        self._engine.dispose()
 
 
 class MySQLManager(SQLManager):
@@ -103,6 +105,8 @@ class MySQLManager(SQLManager):
             self._url.replace('template1', ''))
         self._conn = self._engine.connect()
         self._conn.execute('CREATE DATABASE %s;' % self._db_name)
+        self._conn.close()
+        self._engine.dispose()
 
 
 class ElasticSearchManager(fixtures.Fixture):

setup-test-env-postgresql.sh

@@ -27,7 +27,7 @@ PGSQL_PORT=9823
 ${PGSQL_PATH}/initdb -E UTF8 ${PGSQL_DATA}
 trap "clean_exit_pgsql ${PGSQL_PATH} ${PGSQL_DATA} ${PGSQL_PORT}" EXIT
 
-LANGUAGE=C ${PGSQL_PATH}/pg_ctl -w -D ${PGSQL_DATA} -o "-N 100 -F -k ${PGSQL_DATA} -p ${PGSQL_PORT}" start
+LANGUAGE=C ${PGSQL_PATH}/pg_ctl -w -D ${PGSQL_DATA} -o "-F -k ${PGSQL_DATA} -p ${PGSQL_PORT}" start
 export CEILOMETER_TEST_PGSQL_URL="postgresql:///?host=${PGSQL_DATA}&port=${PGSQL_PORT}&dbname=template1"
 
 # Yield execution to venv command