Add explicit appveyor.yml
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 0000000..365a90b
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,5 @@
+install:
+- cmd: C:\Python27\Scripts\pip.exe install flake8
+build: off
+test_script:
+- cmd: python run.py ci