Add route helper

[josephmancuso]

Closes #199

---

If we have a route list like this:

ROUTES = [
    get('/url/to/dashboard' ..).name('dashboard'),
    get('/profile/user/@id:int/edit').name('profile.edit')
]

We can now use:

def show(self):
    request().route('profile.edit', {'id': 1})

or use the new helper function this comes with:

def show(self):
    route('profile.edit', {'id': 1})

[coveralls]

Coverage decreased (-0.07%) to 91.125% when pulling bf948a3 on add-route-helper into fa3d82a on master.

[coveralls]

Coverage decreased (-0.07%) to 91.125% when pulling bf948a3 on add-route-helper into fa3d82a on master.