Allow passing a custom protocol.

This allows swagger definitions to work properly when the API is behind
an SSL terminator.
Merge tag 'v1.2.6'

1.2.6
Add required swagger 1.2 items property for property type array
Merge branch 'protocol' of github.com:STRML/loopback-explorer into STRML-protocol
Fix the default opts
Merge branch 'STRML-protocol'
Set up default consumes/produces media types

See:

https://github.com/strongloop/loopback/issues/432
https://github.com/wordnik/swagger-js/issues/107
Merge pull request #27 from strongloop/fix/array-items-any

Add required swagger 1.2 items property for property type array
Merge pull request #29 from strongloop/feature/workaround-lb-issue-432

Set up default consumes/produces media types
Bump version
Merge branch 'release/1.2.7' into production