Updated the postgresql.yaml of the dart tests to the correct dbuser and password to fix the authentication errors. These changes are not automated with a python script.

dart-start/postgresql.yaml

@@ -1,5 +1,5 @@
-host: localhost
+host: tfbdata
 port: 5432
-user: postgres
-password: postgres
+user: benchmarkdbuser
+password: benchmarkdbpass
 database: hello_world

dart-stream/postgresql.yaml

@@ -1,5 +1,5 @@
-host: localhost
+host: tfbdata
 port: 5432
-user: postgres
-password: postgres
+user: benchmarkdbuser
+password: benchmarkdbpass
 database: hello_world