code: function(version) {
          var current = [version.major, version.minor, version.patch].join('.');
          var required = '>= 1.6.0';
          if (!semver.satisfies(current, required)) {
            exports.halt();
            grunt.log.writeln();
            grunt.log.errorlns(
              'In order for this task to work properly, PhantomJS version ' +
              required + ' must be installed, but version ' + current +
              ' was detected.'
            );
            grunt.warn('The correct version of PhantomJS needs to be installed.', 127);
          }
        }
docs: Abort if PhantomJS version isn't adequate.