Update branding to 3.1.0-alpha1

eng/Versions.props

@@ -14,9 +14,9 @@
   <!-- Versioning for assemblies/packages -->
   <PropertyGroup>
     <MajorVersion>3</MajorVersion>
-    <MinorVersion>0</MinorVersion>
+    <MinorVersion>1</MinorVersion>
     <PatchVersion>0</PatchVersion>
-    <PreReleaseVersionLabel>rc1</PreReleaseVersionLabel>
+    <PreReleaseVersionLabel>alpha1</PreReleaseVersionLabel>
   </PropertyGroup>
   <!--
     Versioning for tooling releases.