Updated build script to enable building on CI

Author: kichalla

.gitignore

@@ -4,3 +4,4 @@ node_modules/
 npmpackoutput/
 test/webpacktest/package*.json
 test/webpacktest/dist/
+artifacts/

build.msbuild

@@ -5,17 +5,26 @@
     <PropertyGroup>
         <NuspecPath>Microsoft.jQuery.Unobtrusive.Validation.nuspec</NuspecPath>
         <NpmPackOutputDir>$(MSBuildThisFileDirectory)npmpackoutput\</NpmPackOutputDir>
+        <DistDir>$(MSBuildThisFileDirectory)dist\</DistDir>
+        <ArtifactsDir>$(MSBuildThisFileDirectory)artifacts\build\</ArtifactsDir>
         <WebPackTestDir>$(MSBuildThisFileDirectory)test\webpacktest\</WebPackTestDir>
     </PropertyGroup>
 
+    <ItemGroup>
+        <DistDirFiles Include="$(DistDir)*.*"/>
+    </ItemGroup>
+
     <Target Name="Build">
         <ReadLinesFromFile File="@(VersionFile)">
             <Output TaskParameter="Lines" PropertyName="PackageVersion"/>
         </ReadLinesFromFile>
         <Exec Command="npm install" />
         <Exec Command="npm version --no-git-tag-version --allow-same-version $(PackageVersion)" />
         <Exec Command="$(MSBuildThisFileDirectory)node_modules\.bin\gulp" />
-        <Exec Command="nuget pack $(NuspecPath) -Version $(PackageVersion)" />
+        <Copy
+            SourceFiles="@(DistDirFiles)"
+            DestinationFolder="$(ArtifactsDir)" OverwriteReadOnlyFiles="true"/>
+        <Exec Command="nuget pack $(NuspecPath) -Version $(PackageVersion) -OutputDirectory $(ArtifactsDir)" />
 
         <MSBuild Projects ="$(MSBuildProjectFullPath)"
             Properties="PackageVersion=$(PackageVersion)"