add proposalCreation Sample test

agora-test/Spec.hs

@@ -11,6 +11,7 @@ import Test.Tasty (defaultMain, testGroup)
 import Spec.AuthorityToken qualified as AuthorityToken
 import Spec.Effect.TreasuryWithdrawal qualified as TreasuryWithdrawal
 import Spec.Model.MultiSig qualified as MultiSig
+import Spec.Proposal qualified as Proposal
 import Spec.Stake qualified as Stake
 
 -- | The Agora test suite.
@@ -28,6 +29,9 @@ main =
       , testGroup
           "Stake tests"
           Stake.tests
+      , testGroup
+          "Proposal tests"
+          Proposal.tests
       , testGroup
           "Multisig tests"
           [ testGroup