Ensure Re-use cardano-testnet processes

In order for all tests to re-use cardano-testnet processes all tests
need to be wrapped in the same group thus the `testTestnetContracts`
statement must wrap the `group` statement and not the other way round

offchain/test/Main.purs

@@ -51,8 +51,8 @@ pureSuite = do
 
 testnetSuite :: TestPlanM (Aff Unit) Unit
 testnetSuite = do
-  group "Testnet integration tests" do
-    testTestnetContracts config do
+  testTestnetContracts config do
+    group "Testnet integration tests" do
       IlliquidCirculationSupply.suite
       Reserve.suite
       InitMint.suite