[Routing] add missing unit tests for Route and RouteCollection classes

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | none
| License       | MIT
| Doc PR        | none

Just add few unit tests in Route and RouteCollection classes to have a full coverage.