title: add new op to tensorflow on google colab
body: <p>I'm trying to compile some .cc  files on google colab (as shown <a href="https://github.com/tensorflow/models/tree/master/tutorials/embedding" rel="nofollow noreferrer">here</a> &amp; <a href="https://www.tensorflow.org/guide/extend/op#define_the_ops_interface" rel="nofollow noreferrer">here</a>) but I cannot find op.h file to include
  I get the following error while compiling :</p>
  
  <pre><code>word2vec_ops.cc:16:10: fatal error: tensorflow/core/framework/op.h: No such file or directory
  #include "tensorflow/core/framework/op.h"
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.
  word2vec_kernels.cc:16:10: fatal error: tensorflow/core/framework/op.h: No such file or directory
  #include "tensorflow/core/framework/op.h"
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.
  </code></pre>