Update version and readme (#53)

* bump version

* update readme

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "spartan"
-version = "0.6.0"
+version = "0.7.0"
 authors = ["Srinath Setty <srinath@microsoft.com>"]
 edition = "2021"
 description = "High-speed zkSNARKs without trusted setup"

README.md

@@ -33,7 +33,7 @@ We now highlight Spartan's distinctive features.
 To import `libspartan` into your Rust project, add the following dependency to `Cargo.toml`:
 
 ```text
-spartan = "0.4.1"
+spartan = "0.7.0"
 ```
 
 The following example shows how to use `libspartan` to create and verify a SNARK proof.