feat: Converting hoodie.id() to hoodie.id getter

BREAKING CHANGE: hoodie.id() was a method to return the id, but we are
converting it to a getter (see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get)

fixes #11

index.js

@@ -7,16 +7,19 @@ var ConnectionStatus = require('hoodie-client-connection-status')
 var Log = require('hoodie-client-log')
 
 var getState = require('./lib/get-state')
-var id = require('./lib/id').id
+var id = require('./lib/id')
 
 function Hoodie (options) {
   var state = getState(options)
 
-  var api = {}
-  api.id = id.bind(null, state)
+  var api = {
+    get id () {
+      return id.get(state)
+    }
+  }
 
   var CustomStore = Store.defaults({ remoteBaseUrl: '/hoodie/store/api' })
-  var dbName = 'user/' + api.id()
+  var dbName = 'user/' + api.id
   api.store = new CustomStore(dbName)
 
   api.account = new Account({ url: '/hoodie/account/api' })

lib/id.js

@@ -1,5 +1,5 @@
 module.exports = {
-  id: id,
+  get: get,
   set: set,
   unset: unset
 }
@@ -9,7 +9,7 @@ var config = require('humble-localstorage')
 var constants = require('./constants')
 var generateId = require('./utils/generate-id')
 
-function id (state) {
+function get (state) {
   if (!state.id) {
     set(state, generateId())
   }