Add deprecation warning when using ExpressRoutes w/wildcards in v2

[jeffposnick]

Library Affected:
workbox-routing

As discussed on Slack, we're unlikely to support ExpressRoute in v3 (at least not as part of workbox-routing). We will instead treat string paths passed in to registerRoute() as being exact matches against the path or full href of the incoming URL.

To pave the way for this new behavior, we should cut a new v2 patch release that adds in a log message explaining the upcoming change in v3. This message should be triggered whenever a developer creates a route using a string that has special meaning in ExpressRoute.

Based on https://github.com/pillarjs/path-to-regexp#parameters, the following characters should trigger the message:

• :
• ?
• *
• +

[gauntface]

SGTM