Panic on google.Drive.BuildFileHierarchy recursion

[mrksmrtn]

google.Drive.BuildFileHierarchy is a recursive function that returns nil when it encounters a Google Drive API error. This can cause a panic when a recursive call fails its API call and returns nil. This is because google/Drive.go line 191 does not check the result of calling BuildFileHierarchy for nil.

This error was discovered when a Google Drive API call returned a userRateLimitExceeded response.