handle optional request agentOptions

[cconcannon]

This commit resolves issue #67 by passing an optional property requestAgentOptions to set the request library's agentOptions property. Setting agentOptions allows, for example, a trust of private certificate authorities to be established.

An example to trust a private certificate authority chain for a private network jwks_uri:

const jwksClient = require("./node-jwks-rsa");
const fs = require("fs");
const path = require("path");
const caFile = path.resolve(__dirname, "ssl/ca-bundle.pem");

const client = jwksClient({
  jwksUri: "https://my-private-ca-tls-endpoint/ext/oauth2/jwks",
  requestAgentOptions: {
    ca: fs.readFileSync(caFile)
  }
});

Tests have been added to ensure that:

1. the agentOptions are set when JwksClient is configured with the optional requestAgentOptions property

2. the agentOptions are not set by default

[amir-bio]

Thank you for the PR. It would be great if you also added a note to the README as well and link to https://github.com/request/request#using-optionsagentoptions

[cconcannon]

@amirha97 I updated the README with an example config to provide a private certificate authority, and I linked to the request library agentOptions documentation as requested. Thanks for reviewing.

[raijinsetsu]

Is this going anywhere? It looks like it's been stuck for a few months.

[luisrudge]

released in [email protected]