Add appveyor.yml file to configure build settings

This change adds an appveyor.yml file to configure AppVeyor
settings that are used for build runs.  This file will be used
in the future for configuring the version number for release
builds.

Author: daviwil

appveyor.yml

@@ -0,0 +1,32 @@
+version: 0.1.0.{build}
+os: Unstable
+configuration: Release
+clone_depth: 10
+
+branches:
+  only:
+  - master
+
+assembly_info:
+  patch: true
+  file: '**\AssemblyInfo.*'
+  assembly_version: '0.1.0'		# This version number should always have 0 for the last section
+  assembly_file_version: '{version}'
+  assembly_informational_version: '{version}'
+
+install:
+- git submodule -q update --init
+
+before_build:
+- nuget restore
+
+build:
+  project: PowerShellEditorServices.sln
+  publish_nuget: true
+  verbosity: minimal
+
+test:
+  assemblies:
+  - Microsoft.PowerShell.EditorServices.Test.dll
+  - Microsoft.PowerShell.EditorServices.Test.Host.dll
+  - Microsoft.PowerShell.EditorServices.Test.Transport.Stdio.dll