Adding Windows testing via appveyor

Author: mattfarina

appveyor.yml

@@ -0,0 +1,26 @@
+
+version: build-{build}.{branch}
+
+clone_folder: C:\gopath\src\github.com\Masterminds\vcs
+shallow_clone: true
+
+environment:
+  GOPATH: C:\gopath
+
+platform:
+  - x64
+
+install:
+  - go version
+  - go env
+  - choco install -y bzr
+  - set PATH=C:\Program Files (x86)\Bazaar;%PATH%
+  - bzr --version
+
+build_script:
+  - go install -v ./...
+
+test_script:
+  - go test -v
+
+deploy: off