Task#574

[buhongw7583c]

Closes #475

What this PR does / why we need it:
The PR is to add unhappy controller test cases for postgresql server, database and firewall rules.
Special notes for your reviewer:

The controller test should all passed.

make BUILD_TAGS=psqlserver test-existing-controllers

2020/04/14 13:05:22 finished common controller test setup
=== RUN   TestPSQLServerControllerNoResourceGroup
=== PAUSE TestPSQLServerControllerNoResourceGroup
=== CONT  TestPSQLServerControllerNoResourceGroup
--- PASS: TestPSQLServerControllerNoResourceGroup (9.07s)
PASS
2020/04/14 13:05:31 Started common controller test teardown
2020/04/14 13:05:37 Finished common controller test teardown
ok      github.com/Azure/azure-service-operator/controllers     134.617s

make BUILD_TAGS=psqldatabase test-existing-controllers

=== RUN   TestPSQLDatabaseControllerNoResourceGroup
=== PAUSE TestPSQLDatabaseControllerNoResourceGroup
=== RUN   TestPSQLDatabaseControllerNoSever
=== PAUSE TestPSQLDatabaseControllerNoSever
=== CONT  TestPSQLDatabaseControllerNoResourceGroup
=== CONT  TestPSQLDatabaseControllerNoSever
--- PASS: TestPSQLDatabaseControllerNoResourceGroup (9.08s)
--- PASS: TestPSQLDatabaseControllerNoSever (15.09s)
PASS
2020/04/14 16:21:50 Started common controller test teardown
2020/04/14 16:21:55 Finished common controller test teardown
ok      github.com/Azure/azure-service-operator/controllers     181.847s

make BUILD_TAGS=psqlfirewallrule test-existing-controllers

=== RUN   TestPSQLFirewallRuleControllerNoResourceGroup
=== PAUSE TestPSQLFirewallRuleControllerNoResourceGroup
=== RUN   TestPSQLFirewallRuleControllerNoServer
=== PAUSE TestPSQLFirewallRuleControllerNoServer
=== CONT  TestPSQLFirewallRuleControllerNoResourceGroup
=== CONT  TestPSQLFirewallRuleControllerNoServer
--- PASS: TestPSQLFirewallRuleControllerNoServer (6.09s)
--- PASS: TestPSQLFirewallRuleControllerNoResourceGroup (6.11s)
PASS
2020/04/14 15:41:32 Started common controller test teardown
2020/04/14 15:41:37 Finished common controller test teardown
ok      github.com/Azure/azure-service-operator/controllers     33.797s

How does this PR make you feel:

If applicable:

• this PR contains documentation
• this PR contains tests

[WilliamMortlMicrosoft]

lgtm