feat(cli): add support for specifying type and size (#122)

src/bin.js

@@ -3,9 +3,13 @@
 'use strict'
 
 const PeerId = require('./index.js')
+const argv = require('minimist')(process.argv.slice(2))
 
 async function main () {
-  const id = await PeerId.create()
+  const id = await PeerId.create({
+    keyType: argv.type,
+    bits: argv.bits
+  })
   console.log(JSON.stringify(id.toJSON(), null, 2)) // eslint-disable-line no-console
 }