add vagrant image to readme

Author: sb2nov

QSTK/qstkstudy/EventProfiler.py

@@ -75,7 +75,7 @@ def eventprofiler(df_events_arg, d_data, i_lookback=20, i_lookforward=20,
     if b_errorbars == True:
         plt.errorbar(li_time[i_lookback:], na_mean[i_lookback:],
                     yerr=na_std[i_lookback:], ecolor='#AAAAFF',
-                    alpha=0.1)
+                    alpha=0.7)
     plt.plot(li_time, na_mean, linewidth=3, label='mean', color='b')
     plt.xlim(-i_lookback - 1, i_lookforward + 1)
     if b_market_neutral == True:

README.md

@@ -16,6 +16,9 @@ QuantSoftware Toolkit [![PyPI version](https://badge.fury.io/py/QSTK.png)](http:
 - cvxopt >= 1.1.3,
 - scikit-learn >= 0.11
 
+### Vagrant Image
+Vagrant image with QSTK installed can be found at [https://github.com/Wesseldr/vagrant-QSTK](https://github.com/Wesseldr/vagrant-QSTK)
+
 ##Author
 - [Prof. Tucker Balch](http://www.cc.gatech.edu/~tucker/)
 - [Sourabh Bajaj](http://www.sourabhbajaj.com/)