Merge branch 'test-cli' into NAT-66-CLI

test/test_cli.py

+from unittest.mock import patch
+from click.testing import CliRunner
+from resource_management.cli import cli
+
+
+@patch('resource_management.db.init_db_model')
+@patch('resource_management.cli.load_line_cards')
+@patch('resource_management.cli._save_router_info')
+def test_cli_happy_flow(
+        _unused1, _unused2, _unused3,
+        router_name, config_filename):
+    runner = CliRunner()
+    result = runner.invoke(cli, [
+        '--config', config_filename,
+        '--fqdn', router_name])
+    assert result.exit_code == 0
+