Switch to license expression

Author: ejsmith

build/common.props

@@ -18,7 +18,7 @@
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageOutputPath>$(SolutionDir)artifacts</PackageOutputPath>
     <PackageIcon>exceptionless-icon.png</PackageIcon>
-    <PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
+    <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <RepositoryUrl>$(PackageProjectUrl)</RepositoryUrl>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
@@ -37,7 +37,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Include="../../LICENSE.txt" Pack="true" Visible="false" PackagePath="$(PackageLicenseFile)" />
     <None Include="../../build/exceptionless-icon.png" Pack="true" PackagePath="$(PackageIcon)" />
   </ItemGroup>