Add appveyor.yml

.appveyor.yml

@@ -0,0 +1,36 @@
+version: 0.2.0.{build}
+
+clone_folder: C:\GOPATH\src\github.com\osteele\liquid
+
+environment:
+  GOPATH: C:\GOPATH
+
+cache:
+  - C:\mingw64 -> appveyor.yml
+
+init:
+  - set PATH=C:\mingw64\bin;C:\go\bin;%GOPATH%;%PATH%
+  - go version
+  - go env
+  - set CC=gcc
+  - set CXX=g++
+
+install:
+  - ps: |
+      # Install MinGW.
+      $url = "https://bintray.com/artifact/download/drewwells/generic/x86_64-5.1.0-release-win32-seh-rt_v4-rev0.7z"
+      $strFileName="C:\mingw64\bin\mingw32-make.exe"
+      If (Test-Path $strFileName){
+        Write-Host "Using cached mingw64"
+      }Else{
+        Write-Host "Fetching mingw64"
+        Invoke-WebRequest -UserAgent wget -Uri $url -OutFile ming32-64.7z
+        &7z x -oC:\ ming32-64.7z > $null
+      }
+  - go get -t ./...
+  - pip install Pygments
+
+build_script:
+  - go test ./...
+
+platform: x64