Re: RE-SQL tests for Roles & Resource Group nodes

Hi,

PFA patch to add RE-SQL tests for Roles & Resource Group nodes.

=============Running the test cases for 'Regression - PG 11'=============
runTest (regression.re_sql.tests.test_resql.ReverseEngineeredSQLTestCases)
Reverse Engineered SQL Test Cases

Create IMPLICIT Cast
Alter IMPLICIT Cast
Drop IMPLICIT Cast
Create EXPLICIT Cast
Alter EXPLICIT Cast
Drop EXPLICIT Cast


Create Resource groups
 ... 2019-07-01 15:24:16,930: ERROR flask.app: Failed to execute query (execute_scalar) for the server #2 - DB:postgres (Query-id: 1562639):
Error Message:ERROR:  syntax error at or near "RESOURCE"
LINE 1: CREATE RESOURCE GROUP test_resql_resource_group;
               ^

FAIL

======================================================================
FAIL: runTest (regression.re_sql.tests.test_resql.ReverseEngineeredSQLTestCases)
Reverse Engineered SQL Test Cases
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/dpage/git/pgadmin4/web/regression/re_sql/tests/test_resql.py", line 88, in runTest
    self.execute_test_case(scenarios)
  File "/Users/dpage/git/pgadmin4/web/regression/re_sql/tests/test_resql.py", line 145, in execute_test_case
    self.assertEquals(response.status_code, 200)
AssertionError: 500 != 200

----------------------------------------------------------------------
Ran 1 test in 0.767s

FAILED (failures=1)

======================================================================
Test Result Summary
======================================================================

Regression - PG 11:

0 tests passed
1 test failed:
ReverseEngineeredSQLTestCases (Reverse Engineered SQL Test Cases)
0 tests skipped