Add unhappy path for minting limit

cross-chain/solana/tests/02__wormholeGateway.ts

@@ -200,6 +200,25 @@ describe("wormhole-gateway", () => {
  await checkCustodianState(program, authority, 20000);
  });
 
+ it('- won\'t let non-authority update minting limit', async () => {
+ try {
+ await program.methods
+ .updateMintingLimit(new anchor.BN(20000))
+ .accounts({
+ custodian,
+ authority: impostorKeys.publicKey
+ })
+ .signers([impostorKeys])
+ .rpc();
+ chai.assert(false, "should've failed but didn't");
+ } catch (_err) {
+ expect(_err).to.be.instanceOf(AnchorError);
+ const err: AnchorError = _err;
+ expect(err.error.errorCode.code).to.equal('IsNotAuthority');
+ expect(err.program.equals(program.programId)).is.true;
+ }
+ });
+
  it('deposit wrapped tokens', async () => {
  // Set up new wallet
  const payer = await generatePayer(connection, authority.payer);