Update README.md

Author: mueslo

README.md

@@ -1,5 +1,6 @@
 # pythonBits
 [![GitHub release](https://img.shields.io/github/release/mueslo/pythonbits.svg)](https://GitHub.com/mueslo/pythonBits/releases/)
+[![GitHub release](https://img.shields.io/github/release/mueslo/pythonbits.svg?include_prereleases)](https://GitHub.com/mueslo/pythonBits/releases/)
 [![PyPI version](https://img.shields.io/pypi/v/pythonbits.svg)](https://pypi.python.org/pypi/pythonbits/)
 [![PyPI pyversions](https://img.shields.io/pypi/pyversions/pythonbits.svg)](https://pypi.python.org/pypi/pythonbits/)
 [![GitHub commits since release](https://img.shields.io/github/commits-since/mueslo/pythonbits/latest.svg)](https://github.com/mueslo/pythonBits/commits/master)