Updates the Rust compiler to 1.19 (#2920)

* Updates the Rust compiler to 1.19

* Updates Rust Nickel framework to latest version for compatibility with latest compiler

frameworks/Rust/nickel/Cargo.toml

@@ -5,5 +5,5 @@ version = "0.0.1"
 
 [dependencies]
 rustc-serialize = "0.3.19"
-nickel = "0.8.1"
+nickel = "0.10.0"
 nickel_macros = "0.1.0"

toolset/setup/linux/languages/rust.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-RUST_VERSION="1.16.0"
+RUST_VERSION="1.19.0"
 
 fw_installed rust && return 0