feat(core): adds support for nested key lookups (eg key: a.b.c to get nested value in json secret) (#592)

* adds lodash get function for nested keys lookup

* removed semicolon

* added hasIn for nested property check, use get to return nested property value

Author: jonathonbattista

lib/backends/kv-backend.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const AbstractBackend = require('./abstract-backend')
+const { get, hasIn } = require('lodash')
 
 /** Key Value backend class. */
 class KVBackend extends AbstractBackend {
@@ -61,11 +62,11 @@ class KVBackend extends AbstractBackend {
           return
         }
 
-        if (!(property in parsedValue)) {
+        if (!(hasIn(parsedValue, property))) {
           throw new Error(`Could not find property ${property} in ${key}`)
         }
 
-        value = parsedValue[property]
+        value = get(parsedValue, property)
       }
 
       if (isBinary) {