Update readme and re-license to GPLv3

README.md

@@ -1,7 +1,7 @@
-# Zcash Rust crates
+# Hush Rust crates
 
-This repository contains a (work-in-progress) set of Rust crates for
-working with Zcash.
+This repository contains a set of Rust crates for
+working with low-level Hush stuff.
 
 ## Security Warnings
 
@@ -9,16 +9,5 @@ These libraries are currently under development and have not been fully-reviewed
 
 ## License
 
-All code in this workspace is licensed under either of
+GNU Public License 3
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
- * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
-
-at your option.
-
-### Contribution
-
-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
-conditions.