Add gofmt check to appveyor

Author: ChrisSchinnerl

appveyor.yml

@@ -15,11 +15,15 @@ branches:
     - staging
 
 install:
+  - set PATH=%GOPATH%\bin;%PATH%
   - go version
   - go env
   - go get -d ./...
+  - go get github.com/alecthomas/gometalinter
 
 build_script:
+  - gometalinter --install
+  - gometalinter --disable-all -E gofmt ./...
   - go test -tags="testing debug" -short ./...
   - go test -tags="testing debug" -v -timeout=1200s -race ./...
   - go test -tags="testing debug" -v -run=XXX -bench=. ./...