Bump version to 1.2.0 and update changelog.

CHANGELOG.md

@@ -5,6 +5,11 @@
 
 > Nothing yet.
 
+## [1.2.0](https://github.com/SpinResearch/merkle.rs/compare/1.1.0...1.2.0) - 2017-05-07
+
+## Changed
+- Use *ring* 0.9 to reduce build dependencies ([@briansmith](https://github.com/briansmith))
+
 ## [1.1.0](https://github.com/SpinResearch/merkle.rs/compare/1.0.0...1.1.0) - 2017-02-15
 
 ## Added
@@ -14,7 +19,6 @@
 - Avoid allocating memory on the heap in HashUtils, and made `combine_hashes` more efficient ([@briansmith](https://github.com/briansmith))
 - Bump `ring` to `^0.6.0` and `protobuf` to `^1.2.0` ([@romac](https://github.com/romac))
 
-
 ## [1.0.0](https://github.com/SpinResearch/merkle.rs/releases/tag/1.0.0) - 2016-11-29
 
 > Initial release

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name    = "merkle"
-version = "1.1.1-pre"
+version = "1.2.0"
 authors = [
   "Frederic Jacobs <me@fredericjacobs.com>",
   "Dylan Bourgeois <dtsbourg@gmail.com>",