Version v0.91.5

What's Changed

• Adding function to detect whether problem is infeasible or an optimal… by @tkralphs in #150
• Always build using setuptools and Cython, remove generated files by @mkoeppe in #153
• Update README.rst by @mkoeppe in #156
• Add integration testing with CVXPY by @mkoeppe in #155

Full Changelog: v0.91.4...v0.91.5