Set Go 1.5 vendoring condition correctly
Set Go 1.5 vendoring condition correctly

We use `[[]]` for `sh.if`, which evaluates `[[ false ]]` to true,
so returning `false` will cause all versions of Go to skip the
`-f Godeps/Godeps.json` condition.

We return an obviously false condition here, to avoid this.

JuliaCI/travis-build,craigcitro/travis-build,jhass/travis-build,JuliaCI/travis-build,kevmoo/travis-build,jhass/travis-build,akoeplinger/travis-build,craigcitro/travis-build,akoeplinger/travis-build,kevmoo/travis-build,andyli/travis-build,andyli/travis-build