Add options for jwks-rsa to enable cache and rate limiting

[cdwills]

Add options to take advantage of the built in caching from jwks-rsa. Description is here: https://github.com/auth0/node-jwks-rsa#caching

To see the caching in action add DEBUG=jwks to your local env for the previous version vs this one. You'll see the caching configured and in action.

Bonus:

• bumped eslint, nyc, nock
• bumped boom
• added option to run Travis tests in node 10.

• I believe we can remove support for node 6, 7 in the future.

[dbertram]

One possible bug around merging of jwks option defaults, but otherwise lgtm

[cdwills]

@dbertram great catch on the merge, i changed it up. Tested locally and feeling good about this. Would like some final 👀

[dbertram]

Looks like one piece of 🧹ing left and this lgtm

[dbertram]

[pklingem]

👀

[pklingem]

just the one comment, other than that, I can confirm that I'm seeing caching on my side. First request shows the keys, subsequent requests do not.

[pklingem]

the options section is a bit confusing. Am I correct that any options other that jwks or issWhitelist will be passed to jwt.verify()? If so, should it be:

{
  verify: { ... },
  jwks: { ... },
  issWhitelist: ...,
}

for some futureproofing? It seems odd to separate jwks' options, but not verify's and I could imagine that causing conflicts eventually.

[dbertram]

@pklingem @cdwills Looks like the CI builds are failing due to reduced code coverage:

ERROR: Coverage for branches (80%) does not meet global threshold (100%)
----------|----------|----------|----------|----------|-------------------|
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files | 100 | 80 | 100 | 100 | |
index.js | 100 | 80 | 100 | 100 | 45,46 |
----------|----------|----------|----------|----------|-------------------|
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
The command "yarn run test:ci" exited with 1.

:sadpanda:

[cdwills]

💯

[dbertram]