fix tests

Author: yyx990803

src/devtools/global.styl

@@ -81,7 +81,7 @@ $arrow-color = #444
   opacity 0
   transform translate(0, 50%)
 
-.slide-up-leave-active
+.slide-up-leave-to
   opacity 0
   transform translate(0, -50%)
 

test/specs/test.js

@@ -3,6 +3,7 @@ module.exports = {
     browser
     .url('http://localhost:' + (process.env.PORT || 8081))
       .waitForElementVisible('.message', 1000)
+      .waitFor(1000) // wait for entering animation
       .assert.containsText('.message', 'Ready. Detected Vue')
       .assert.elementPresent('.instance')
       .assert.containsText('.instance', 'Root')