Relax development dependencies
Relax development dependencies

Both Nokogiri and RSpec were pinned at a specified version. They're
relatively stable projects that don't break backwards compatibility
without a good reason, so in the interest of ensuring our dependencies
are up-to-date, relax their constraints.

Change-Id: Ia1e44ac9aa76c2322a61cd38430175b9ece3392a
Reviewed-on: http://gerrit.causes.com/36731
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@causes.com>
Reviewed-by: Shane da Silva <6f6e68d1df92f30cb4b3ce35260ddf94a402f33d@causes.com>

gajus/scss-lint,chatzipan/scss-lint,dwayhs/scss-lint,golmansax/scss-lint,baileyparker/scss-lint,teoljungberg/scss-lint,philipgiuliani/scss-lint,ivantsepp/scss-lint,leseulsteve/scss-lint,gatero/scss-lint,ingdir/scss-lint,bkeepers/scss-lint,cih/scss-lint,davecarter/scss-lint