[travis] Move before_install step to install steps
[travis] Move before_install step to install steps

This doesn't need to happen before the install step, it can happen as
part of the install step

solarnz/tchaik,GrahamGoudeau21/tchaik,GrahamGoudeau21/tchaik,tchaik/tchaik,solarnz/tchaik,solarnz/tchaik,tchaik/tchaik,GrahamGoudeau21/tchaik,solarnz/tchaik,tchaik/tchaik,tchaik/tchaik,GrahamGoudeau21/tchaik