Make testutils dependency path relative

Cargo.toml

@@ -60,8 +60,8 @@ test-electrum = ["electrum"]
 test-md-docs = ["electrum"]
 
 [dev-dependencies]
-bdk-testutils = "0.2"
-bdk-testutils-macros = "0.2"
+bdk-testutils = { path = "./testutils" }
+bdk-testutils-macros = { path = "./testutils-macros" }
 serial_test = "0.4"
 lazy_static = "1.4"
 env_logger = "0.7"