fix version number in news
[![PyPI version](https://img.shields.io/pypi/v/BenchExec.svg)](https://pypi.python.org/pypi/BenchExec)
**News**:
-- BenchExec 1.15 adds [energy measurements](https://github.com/sosy-lab/benchexec/blob/master/doc/resources.md#energy)
+- BenchExec 1.16 adds [energy measurements](https://github.com/sosy-lab/benchexec/blob/master/doc/resources.md#energy)
if the tool [cpu-energy-meter](https://github.com/sosy-lab/cpu-energy-meter) is installed on the system.
- An extended version of our paper on BenchExec and its background gets published in [STTT](http://sttt.cs.uni-dortmund.de/index.html),
you can now read the preprint of [Reliable Benchmarking: Requirements and Solutions](https://www.sosy-lab.org/~dbeyer/Publications/2017-STTT.Reliable_Benchmarking_Requirements_and_Solutions.pdf).
