Add test locations [SERINA-7]
Translate addresses into url [SERINA-7]
Obtain Google Maps Directions API result via curl [SERINA-7]
Move api url into class var [SERINA-7]
Add some auxiliary Collection methods [SERINA-7]
Off-by-one fix [SERINA-7]
Add retrieveUrl() method [SERINA-7]

This constructs a Google Maps Directions API url with injected origins,
destinations and optional intermediary waypoints.