Merge #317: Update simplicity-lang dependency version to 0.6 on README

fa05454 Update simplicity-lang dependency version to 0.6 on README (Shigeru Myamoto)

Pull request description:

  The example in `Quick Start` implies the use of `Context::with_context` thats only available in 0.6


ACKs for top commit:
  apoelstra:
    ACK fa05454; successfully ran local tests


Tree-SHA512: 4cfeae6b281ea9c66519566fcbc127e945b91f701bc8b56c3ac30f7d8bfebd73fb1e62f3906edc2cde8dc334639ebabf39104a04a647f5128b69b05b887b6918

Author: apoelstra

README.md

@@ -50,7 +50,7 @@ To use rust-simplicity, this to your Cargo.toml:
 
 ```toml
 [dependencies]
-simplicity-lang = "0.5"
+simplicity-lang = "0.6"
 ```
 
 ## Quick Start