e2e: stop referring to protractor as `ptor` and no getInstance()

ptor makes itself global as `browser`, always use that reference.

Also, don't try to call getInstance because the function no longer
exists.
browser: back to node-sass 1.0.3

Inadvertently updated to more recent version which does not work in
RHEL 6.x.
e2e: don't do extra work to install node-sass

Attempt to run node-sass "as is" in travis, thus do not install updates
to build dependencies in .travis.yml.