Remove unneeded/repeated Travis steps
Remove unneeded/repeated Travis steps

Some steps are now being run with Go tip and not in all the different versions,
there were also moved to their own block so they will fail fast and in the mean
time the unit test for the different versions can start.

Also, "make docs" was removed because it's already being done by "make" without
any argument.

Fixes #1400.

Signed-off-by: Álex González <ebbdfb7c41974a633a6ef76d601adc133f19bf2d@gmail.com>

kubernetes-incubator/ocid,mikebrow/cri-o,kubernetes-incubator/cri-o,vbatts/cri-o,vbatts/cri-o,rhatdan/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,rhatdan/cri-o,mikebrow/cri-o,mikebrow/cri-o,jwhonce/ocid,rhatdan/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,vbatts/cri-o,jwhonce/ocid,nalind/cri-o,mikebrow/cri-o,kubernetes-incubator/ocid,jwhonce/ocid,vbatts/cri-o,nalind/cri-o,rhatdan/cri-o,kubernetes-incubator/cri-o