message: Fix string.Join method to work on Unity 2017.4
diff: @@ -14,6 +14,7 @@ limitations under the License.
  ==============================================================================*/
  using System;
  using System.Runtime.InteropServices;
  +using System.Linq;
  using TfLiteInterpreter = System.IntPtr;
  using TfLiteInterpreterOptions = System.IntPtr;
  @@ -48,7 +49,7 @@ namespace TensorFlowLite
  return string.Format("name: {0}, type: {1}, dimensions: {2}, quantizationParams: {3}",
  name,
  type,
  - "[" + string.Join(",", dimensions) + "]",
  + "[" + string.Join(",", dimensions.Select(d => d.ToString()).ToArray()) + "]",
  "{" + quantizationParams + "}");
  }
  }
  