Accept keyringTypes via options param

[brunobar79]

Based on the usage example, we should be able to optionally pass an array of keyringTypes

[danfinlay]

Cool, makes the whole module more customizable.

[danfinlay]

Published as eth-keyring-controller@3.2.0

npm notice
npm notice 📦  eth-keyring-controller@3.2.0
npm notice === Tarball Contents ===
npm notice 1.3kB  package.json
npm notice 14.9kB index.js
npm notice 1.8kB  README.md
npm notice 960B   .circleci/config.yml
npm notice 3.0kB  docs/keyring.md
npm notice 1.6kB  test/helper.js
npm notice 5.7kB  test/index.js
npm notice 5.7kB  test/lib/config-manager.js
npm notice 517B   test/lib/config.js
npm notice 326B   test/lib/first-time-state.js
npm notice 310B   test/lib/mock-config-manager.js
npm notice 613B   test/lib/mock-encryptor.js
npm notice === Tarball Details ===
npm notice name:          eth-keyring-controller
npm notice version:       3.2.0
npm notice package size:  10.9 kB
npm notice unpacked size: 36.7 kB
npm notice shasum:        e92f2581b9ccb007d6e614e5749dc5786f133b4c
npm notice integrity:     sha512-GU1blKGftP6VD[...]I1CdNWdAzZg5w==
npm notice total files:   12
npm notice