Added a function to save a Config.

src/client/data/config.rs

@@ -5,7 +5,7 @@ use std::fs::File;
 use std::io::prelude::*;
 use std::io::{Error, ErrorKind, Result};
 use std::path::Path;
-use rustc_serialize::json::decode;
+use rustc_serialize::json::{decode, encode};
 
 /// Configuration data.
 #[derive(Clone, RustcDecodable, RustcEncodable, Default, PartialEq, Debug)]
@@ -55,6 +55,14 @@ impl Config {
         )
     }
 
+    /// Saves a JSON configuration to the desired path.
+    pub fn save<P: AsRef<Path>>(&self, path: P) -> Result<()> {
+        let mut file = try!(File::create(path));
+        file.write_all(try!(encode(self).map_err(|_|
+            Error::new(ErrorKind::InvalidInput, "Failed to encode configuration file.")
+        )).as_bytes())
+    }
+
     /// Determines whether or not the nickname provided is the owner of the bot.
     pub fn is_owner(&self, nickname: &str) -> bool {
         self.owners.as_ref().map(|o| o.contains(&nickname.to_string())).unwrap()