Add a space to the Flutter SDK path on Appveyor (flutter#14615)

cbracken · web-flow · commit a6135a67bf43 · 2018-02-10T13:43:10.000-08:00
Ensures we don't regress flutter#6577 on Windows.
diff --git a/appveyor.yml b/appveyor.yml
@@ -1,4 +1,7 @@
 install:
+- cmd: cd ..
+- cmd: move flutter "flutter sdk"
+- cmd: cd "flutter sdk"
 - cmd: bin\flutter.bat config --no-analytics
 - cmd: bin\flutter.bat update-packages
 
