[doc] Add the bug fix information for ipython user (automl#254)

* [doc] Add the bug fix information for ipython user

* [fix] Delete the gcc and gnn install because I could check we can build without them

README.md

@@ -27,11 +27,7 @@ git submodule update --init --recursive
 # Create the environment
 conda create -n autopytorch python=3.8
 conda activate autopytorch
-For Linux:
-    conda install gxx_linux-64 gcc_linux-64 swig
-For mac:
-    conda install -c conda-forge clang_osx-64 clangxx_osx-64
-    conda install -c anaconda swig
+conda install swig
 cat requirements.txt | xargs -n 1 -L 1 pip install
 python setup.py install