Add a config file for appveyor.com Windows CI testing.

Adapted from http://blogs.perl.org/users/eserte/2016/04/testing-with-appveyor.html

Windows is known to not be working. See #297.

Signed-off-by: Michael G. Schwern <schwern@pobox.com>

appveyor.yml

@@ -0,0 +1,21 @@
+branches:
+  except:
+    - /travis/
+skip_tags: true
+
+cache:
+  - C:\strawberry
+
+install:
+  - if not exist "C:\strawberry" cinst strawberryperl
+  - set PATH=C:\strawberry\perl\bin;C:\strawberry\perl\site\bin;C:\strawberry\c\bin;%PATH%
+  - cd C:\projects\%APPVEYOR_PROJECT_NAME%
+  - cpanm --installdeps .
+
+build_script:
+  - perl Build.PL
+  - ./Build
+
+test_script:
+  - ./Build test
+