fix(ci): support pre-release versions in tags

Author: jaredcnance

Build.ps1

@@ -14,9 +14,21 @@ echo "VERSION-SUFFIX: alpha1-$revision"
 
 If($env:APPVEYOR_REPO_TAG -eq $true) {
     echo "RUNNING dotnet pack .\src\JsonApiDotNetCore -c Release -o .\artifacts "
-    dotnet pack .\src\JsonApiDotNetCore -c Release -o .\artifacts 
+    $revision = Get-Version-Suffix-From-Tag
+    dotnet pack .\src\JsonApiDotNetCore -c Release -o .\artifacts --version-suffix=alpha1-$revision 
 }
 Else { 
     echo "RUNNING dotnet pack .\src\JsonApiDotNetCore -c Release -o .\artifacts --version-suffix=alpha1-$revision"
     dotnet pack .\src\JsonApiDotNetCore -c Release -o .\artifacts --version-suffix=alpha1-$revision 
 }
+
+# Gets the version suffix from the repo tag
+# example: v1.0.0-preview1-final => preview1-final
+function Get-Version-Suffix-From-Tag
+{
+  $tag=$env:APPVEYOR_REPO_TAG_NAME
+  $split=$tag -split "-"
+  $suffix=$split[1..2]
+  $final=$suffix -join "-"
+  return $c
+}