Drop outdated caffe2 section

Author: nicolasvasilache

docs/source/framework/caffe2_integration/installation_caffe2_integration.rst

@@ -43,13 +43,6 @@ Machine Learning.
    framework/pytorch_integration/debugging
    framework/pytorch_integration/frequently_asked_questions
 
-.. toctree::
-   :maxdepth: 1
-   :caption: Caffe2 Integration
-
-   framework/caffe2_integration/integration_with_example
-   framework/caffe2_integration/installation_caffe2_integration
-
 .. toctree::
    :maxdepth: 1
    :caption: Installation