readme: updated install command for new Anaconda versions 2018

Author: conkerts

README.md

@@ -32,9 +32,9 @@ Or for current versions of Anaconda (Mar 2018)
  
 $ conda create -n skl_tut python=3.4.5 ipywidgets=5.2.2 numpy scipy matplotlib scikit-learn ipython-notebook seaborn pillow
 
-activate skl_tut
+$ activate skl_tut
 
-jupyter notebook --notebook-dir='<tutorial folder>'
+$ jupyter notebook --notebook-dir='<tutorial folder>'
 ```
 
 Alternatively, you can download and install the (very large) Anaconda software distribution, found at https://store.continuum.io/.