add pypi version badge

Author: benvanwerkhoven

README.rst

@@ -1,7 +1,7 @@
 Kernel Tuner: A Search-Optimizing GPU Code Auto-Tuner
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-|Build Status| |Codacy Badge| |Codacy Badge2|
+|Build Status| |Codacy Badge| |Codacy Badge2| |PyPi Badge|
 
 Kernel Tuner simplifies the software development of optimized and auto-tuned GPU programs, by enabling Python-based unit testing of GPU code and making it easy to develop scripts for auto-tuning GPU kernels. This also means no extensive changes and no new dependencies are required in the kernel code. The kernels can still be compiled and used as normal from any host programming language.
 
@@ -156,3 +156,5 @@ spent on tuning kernels.
    :target: https://www.codacy.com/app/b-vanwerkhoven/kernel_tuner
 .. |Codacy Badge2| image:: https://api.codacy.com/project/badge/coverage/016dc85044ab4d57b777449d93275608
    :target: https://www.codacy.com/app/b-vanwerkhoven/kernel_tuner
+.. |PyPi Badge| image:: https://img.shields.io/pypi/v/kernel_tuner.svg?colorB=blue 
+   :target: https://pypi.python.org/pypi/kernel_tuner/