Update appveyor.yml

revert build change
diff --git a/appveyor.yml b/appveyor.yml
index 5848228..a0eb0c9 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -4,6 +4,8 @@
 
 install:
   - choco install -y dart-sdk -version 1.10.0
+  - set PATH=%PATH%;C:\tools\dart-sdk\bin		
+  - set PATH=%PATH%;%APPDATA%\Pub\Cache\bin
   - pub get
 
 build: off