Add Appveyor configuration

appveyor.yml

@@ -0,0 +1,20 @@
+environment:
+  matrix:
+    - PYTHON: "C:\\Python27"
+    - PYTHON: "C:\\Python27-x64"
+    - PYTHON: "C:\\Python35"
+    - PYTHON: "C:\\Python35-x64"
+    - PYTHON: "C:\\Python36"
+    - PYTHON: "C:\\Python36-x64"
+
+install:
+  - "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
+  - "python --version"
+  - "python -c \"import struct; print(struct.calcsize('P') * 8)\""
+  - "pip install --disable-pip-version-check --user --upgrade pip"
+  - "pip install -r requirements-dev.txt"
+
+build: off
+
+test_script:
+  - "python -m pytest -s -v pyswagger/tests"