chore: use lodash main dependency

Author: vasco-santos

package.json

@@ -45,7 +45,7 @@
     "async": "^2.6.1",
     "interface-datastore": "~0.4.2",
     "libp2p-crypto": "~0.13.0",
-    "lodash.merge": "^4.6.1",
+    "lodash": "^4.6.1",
     "pull-stream": "^3.6.8",
     "sanitize-filename": "^1.6.1"
   },

src/keychain.js

@@ -2,7 +2,7 @@
 'use strict'
 
 const sanitize = require('sanitize-filename')
-const deepmerge = require('lodash.merge')
+const deepmerge = require('lodash/merge')
 const crypto = require('libp2p-crypto')
 const DS = require('interface-datastore')
 const pull = require('pull-stream')