route syntax sugar improvement, eliminate side effects

[kristofsajdak]

Looking back at the harvester.route (e.g. readonly, immutable... ) methods I now feel that it's making things complex and rigid with not enough benefit.

As part of this change I removed the side-effecting harvester.route functions in favour of pure functions which got added to harvester.routes alongside with the singular route methods (e.g. get, post...)

Rather than

harvester.route.readonly(brands) 

we now declare

_.map(harvester.routes.readonly(brands), (route) => server.route(route))

and analogue

_.map(harvester.routes.all(brands), (route) => server.route(route))
_.map(harvester.routes.readonly(brands), (route) => server.route(route))
_.map(harvester.routes.immutable(brands), (route) => server.route(route))

It's a bit more verbose but composes a lot better, as it allows the resulting route object literals to be passed around and transformed with libs such as lodash and (ramdbajs)[http://ramdajs.com/]