It appears some changes in go 1.13 require larger key sizes.

This test failed with "key size too small for PSS signature".

middleware/jwt_test.go

@@ -981,7 +981,7 @@ func TestJwtWrongSigningMethod(t *testing.T) {
 	// Setup pre-req bits needed to make our PS256 valid.
 	// Should we use a fake source of randomness instead of real
 	// rand.Reader here?
-	pk, err := rsa.GenerateKey(rand.Reader, 256*2)
+	pk, err := rsa.GenerateKey(rand.Reader, 512*2)
 	tests.Assert(t, err == nil, "rsa.GenerateKey failed:", err)
 	tokenString, err := token.SignedString(pk)
 	tests.Assert(t, err == nil, "token.SignedString failed:", err)