Switch install plugin to send status codes instead of full strings.

lib/roles/device/plugins/install.js

@@ -57,7 +57,7 @@ module.exports = syrup.serial()
               if (contentLength) {
                 // Progress 0% to 70%
                 sendProgress(
-                  'Pushing app to the device'
+                  'pushing_file'
                 , 70 * Math.max(0, Math.min(
                     70
                   , stats.bytesTransferred / contentLength
@@ -87,11 +87,11 @@ module.exports = syrup.serial()
       }
 
       // Progress 0%
-      sendProgress('Pushing app to the device', 0)
+      sendProgress('pushing_file', 0)
       pushApp()
         .then(function(apk) {
           // Progress 80%
-          sendProgress('Installing app', 80)
+          sendProgress('installing_app', 80)
           return adb.installRemote(options.serial, apk)
         })
         .timeout(10000)
@@ -103,7 +103,7 @@ module.exports = syrup.serial()
             , message.launchActivity.component
             )
             // Progress 90%
-            sendProgress('Launching activity', 90)
+            sendProgress('launching_app', 90)
             return adb.startActivity(options.serial, message.launchActivity)
           }
         })
@@ -115,7 +115,7 @@ module.exports = syrup.serial()
               options.serial
             , seq++
             , true
-            , 'Installation complete'
+            , 'success'
             ))
           ])
         })
@@ -127,7 +127,7 @@ module.exports = syrup.serial()
               options.serial
             , seq++
             , false
-            , 'Installation failed'
+            , 'fail'
             ))
           ])
         })