Switch to GPLv3 license

Author: LinuxMercedes

Cargo.toml

@@ -5,7 +5,7 @@ authors = ["LinuxMercedes <LinuxMercedes@gmail.com>"]
 description = "Unix pipes + IRC"
 repository = "https://github.com/LinuxMercedes/hashpipe"
 readme = "README.md"
-license = "MIT"
+license = "GPLv3"
 
 [dependencies]
 irc = "0.11.0"