Update build script and ensure sass is installed on appveyor

Author: rasmusjp

appveyor.yml

@@ -1,9 +1,12 @@
 version: '{build}'
 os: Visual Studio 2017
+shallow_clone: true
 init:
+  - set PATH=C:\Ruby25\bin;%PATH%
   - git config --global core.autocrlf input
   - git config --global core.longpaths true
-shallow_clone: true
+install:
+  - gem install sass
 build_script:
   build.cmd package
 test: off

tools/build.fsx

@@ -27,16 +27,25 @@ Target.create "Clean" (fun _ ->
 )
 
 Target.create "Build" (fun _ ->
+  let setMSBuildParams (defaults:MSBuild.CliArguments) =
+        { defaults with
+            Properties =
+                [
+                    "Version_Suffix", if buildVersion.IsSome then buildVersion.Value else ""
+                ]
+         }
+
   DotNet.build (fun c ->
     { c with
         Configuration = DotNet.BuildConfiguration.Release
-        OutputPath = Some artifactsDir
+        MSBuildParams = setMSBuildParams c.MSBuildParams
     }) solutionFile
 )
 
 Target.create "Package" (fun _ ->
   DotNet.pack (fun c ->
     { c with
+        NoBuild = true
         Configuration = DotNet.BuildConfiguration.Release
         OutputPath = Some artifactsDir
         VersionSuffix = buildVersion
@@ -52,6 +61,7 @@ open Fake.Core.TargetOperators
   ==> "Default"
 
 "Clean"
+  ==> "Build"
   ==> "Package"
 
 // start build