Use the first matched branch configuration

This change causes GitVersion to allow multiple branch configurations to
match the current branch, and instead of throwing an exception it will use
the first matching configuration that was found.

Author: cvpcs

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -16,14 +16,8 @@ public static BranchConfig GetBranchConfiguration(Commit currentCommit, IReposit
         {
             var matchingBranches = LookupBranchConfiguration(config, currentBranch).ToArray();
 
-            if (matchingBranches.Length > 1)
-            {
-                const string format = "Multiple branch configurations match the current branch branchName of '{0}'. Matching configurations: '{1}'";
-                throw new Exception(string.Format(format, currentBranch.FriendlyName, string.Join(", ", matchingBranches.Select(b => b.Name))));
-            }
-
             BranchConfig branchConfiguration;
-            if (matchingBranches.Length == 1)
+            if (matchingBranches.Length > 0)
             {
                 branchConfiguration = matchingBranches[0];
             }