exclude test_data when publishing the crate

Author: RCasatta

Cargo.toml

@@ -9,6 +9,7 @@ documentation = "https://docs.rs/bitcoin/"
 description = "General purpose library for using and interoperating with Bitcoin and other cryptocurrencies."
 keywords = [ "crypto", "bitcoin" ]
 readme = "README.md"
+exclude = ["./test_data"]
 
 # Please don't forget to add relevant features to docs.rs below
 [features]