Added README to tutorials/ recommending to the user to install TensorFlow from source

tutorials/README.md

@@ -0,0 +1,3 @@
+# Tutorial Models
+
+This repository contains models referenced to from the [TensorFlow tutorials](https://www.tensorflow.org/tutorials/). We recommend [installing TensorFlow from source](https://www.tensorflow.org/get_started/os_setup#installing_from_sources) using the current master version rather than the r0.12 release before running these models.