Feature/route guard redirect

[CasperPas]

Implementation for redirect feature mention at #28

This PR included commits from these PRs:

• Pop now returns void #27
• Feature/navigate multiple w params #30

Example

SailorRoute(
  name: 'user_info',
  builder: (context, args, params) => UserInfoPage(),
  routeGuards: [
    SailorRouteGuard.simple((context, args, params) async {
      if (userBloc.isLoggedIn) {
        return true;
      } else {
        // Redirect to login page
        return RouteArgsPair('/login');
      }
    }),
  ],
),

[gurleensethi]

Thanks for the PR.
Appreciate the community's efforts to improve Sailor.
While this does solve the problem, its not the ideal solution. I will be updating the library in coming days, it will be a major refactor and will provide a way where it will allow for redirects.

[rlee1990]

@gurleensethi are there any updates on when this will be released?