plot_bootstrap.py example: mention dependency on rootpy and how to install it
plot_bootstrap.py example: mention dependency on rootpy and how to install it

rootpy/root_numpy,rootpy/root_numpy,scikit-hep/root_numpy,ndawe/root_numpy,scikit-hep/root_numpy,ndawe/root_numpy,scikit-hep/root_numpy,rootpy/root_numpy,rootpy/root_numpy,scikit-hep/root_numpy,ndawe/root_numpy,ndawe/root_numpy