does not work on Apigee edge any more due to const keyword in a downstream dependency

[antxxxx]

This no longer works when deployed to Apigee edge because the runtime on there is v0.10 and one of the dependencies now installed is node-mime v2 which uses the const keyword

The dependency is introduced from the dependency to
https://jl.githost.io/apigee/swagger-tools which depends on
https://github.com/whitlockjc/json-refs (has to be version 2 - version 3 contains some new syntax which also wont work) which depends on
https://github.com/whitlockjc/path-loader which depends on superagent. If the version of superagent in here is specified as 3.6.0 then everything works

So for this to work, path-loader has to specify version 3.6.0 of superagent, json-refs version 2.* has to specify the correct version of path-loader, and swagger-tools has to specify the correct version of json-refs and this has to reference the correct version of swagger-tools