ToDo App - New view to display github

- Removing hardcoded reference to storyboard
- Correcting data array content errors/typos
- Updating didSelectRowAtIndexPath to now instantiate new UIWebView and
then push it via a new UIViewController onto our NavigationController.
Todo App - Now pull user data from GitHub website

- Adding new class GitHubRequest that will connect to GitHub API
website and pull relevant user information based on the given GitHub
username. Specifically, we now parse returned JSON data to extract the
user’s name, their full github URL and their profile image.
- Since we’re dynamically loading images (from the web), deleting all
stored images from the project.
Todo App - Adding swipe to delete functionality

- Extracting reusable method updateFooter
-
Todo App - Adding ability to move/drag and drop items
Todo App - Fixing bugs

- Corrected the moveRowAtIndexPath method to prevent an out of bounds
exception when you try to move an item to the same spot.
- Refactored addNewUser method to extract new method
lookupUserDetailsOnGitHub that can be reused by the init method. This
fixes a bug where we previously would add a user even if we didn’t have
all 3 keys (name, image, github url) set.