Merge pull request #722 from wibblymat/reject-on-spawn-error

Reject the promise for a command if an error event is fired

lib/util/cmd.js

@@ -68,6 +68,11 @@ function cmd(command, args, options) {
         stderr += data;
     });
 
+    // If there is an error spawning the command, reject the promise
+    process.on('error', function (error) {
+        return deferred.reject(error)
+    });
+
     // Listen to the close event instead of exit
     // They are similar but close ensures that streams are flushed
     process.on('close', function (code) {