No need to validate path here

The path is only required to be valid if it happens to get used, which
is not always the case for this constructor. It's already being
validated when it gets used, so avoid doing IO here.

Author: shana

src/GitHub.Exports/Models/SimpleRepositoryModel.cs

@@ -14,8 +14,6 @@ public class SimpleRepositoryModel : NotificationAwareObject, ISimpleRepositoryM
     {
         public SimpleRepositoryModel(string name, UriString cloneUrl, string localPath = null)
         {
-            if (localPath != null && !Directory.Exists(localPath))
-                throw new ArgumentException("Malformed path", localPath);
             Name = name;
             CloneUrl = cloneUrl;
             LocalPath = localPath;
@@ -27,7 +25,7 @@ public SimpleRepositoryModel(string path)
             if (path == null)
                 throw new ArgumentNullException("path");
             if (!Directory.Exists(path))
-                throw new ArgumentException("Malformed path", path);
+                throw new ArgumentException("Path does not exist", path);
             var uri = GitHelpers.GetRepoFromPath(path)?.GetUri();
             var name = uri?.NameWithOwner;
             if (name == null)