Cap 1329 cocoapod updates for 2x

Updates to the cocopad docs and podspec template: 

* Updated README documentation
   * Update min iOS version and sample Artisan Version
   * remove references to --no-doc option, which doesn't exist anymore.
   * Simplify the ARManager startWithId instructions.
* Updated podspec template
   * Summary was too long (max 140 chars)
   * homepage unreachable
   * update documentation link