Update phantomjs to 1.9.8

Resolve redirects not followed as n1k0/casperjs#442.
Binary packages of The Phantomjs project is provided by Bitbucket since
version 1.9.6.
Follow redirects

curl does not follow redirects by default.
Rename VERSION to PHANTONJS_VERSION
Clearly to use capserjs 1.1-beta

Fix version means stable.
Update versions in README.md
Merge pull request #1 from Gasol/update_casperjs_and_phantomjs

Update casperjs and phantomjs