[travis] fail the coverage if <80%
[travis] fail the coverage if <80%

[ci skip]

vishesh/pycket,samth/pycket,magnusmorton/pycket,pycket/pycket,krono/pycket,samth/pycket,vishesh/pycket,krono/pycket,pycket/pycket,magnusmorton/pycket,samth/pycket,krono/pycket,vishesh/pycket,cderici/pycket,pycket/pycket,magnusmorton/pycket,cderici/pycket,cderici/pycket