Only execute lines with commands.

Fixes #45 and #46.

src/bot.rs

@@ -124,14 +124,14 @@ impl DiceBot {
 
         let mut results = Vec::with_capacity(msg_body.lines().count());
 
-        for command in msg_body.lines() {
-            if !command.is_empty() {
+        let commands = msg_body.trim().lines().filter(|line| line.starts_with("!"));
+
+        for command in commands {
             let ctx = Context::new(&self.db, &room_id.as_str(), &sender_username, &command);
             if let Some(cmd_result) = execute_command(&ctx).await {
                 results.push(cmd_result);
             }
         }
-        }
 
         if results.len() >= 1 {
             if results.len() == 1 {