chore(travis): fix build by doing global npm installs earlier
chore(travis): fix build by doing global npm installs earlier

In 8d3df2bf938fbdea711e5141389b13c2d0fa2e06 I added `bower install` to
the npm `postinstall` script and accidentally broke Travis. The
`.travis.yml` was installing Bower after running `npm install` which
was now too late.

I fixed the order and removed unnecessary `bower install` from
`.travis.yml` (which should’ve been done when the npm `postinstall`
script was updated).

MartinSandstrom/angular-apimock,MartinSandstrom/angular-apimock,seriema/angular-apimock,seriema/angular-apimock