(#284) Skip creation of HEAD branch

- Based on a suggestion from @nulltoken, skipping the creation of the HEAD branch, if it exists in the list of branches to create.
- This was causing an issue when running on AppVeyor
- This can be seen working here:
	https://ci.appveyor.com/project/GaryEwanPark/webapisample/build/0.2.0-unstable.23+23%20(Build%2034)

Author: Gary Ewan Park

GitVersionCore/BuildServers/GitHelper.cs

@@ -176,6 +176,13 @@ static void CreateMissingLocalBranchesFromRemoteTrackingOnes(Repository repo, st
             foreach (var remoteTrackingReference in repo.Refs.FromGlob(prefix + "*"))
             {
                 var localCanonicalName = "refs/heads/" + remoteTrackingReference.CanonicalName.Substring(prefix.Length);
+
+                if (localCanonicalName.EndsWith("HEAD"))
+                {
+                    Logger.WriteInfo(string.Format("Skipping creation of '{0}' as this is not required.", remoteTrackingReference.CanonicalName));
+                    continue;
+                }
+
                 if (repo.Refs.Any(x => x.CanonicalName == localCanonicalName))
                 {
                     Logger.WriteInfo(string.Format("Skipping local branch creation since it already exists '{0}'.", remoteTrackingReference.CanonicalName));