Fix dependencies in 3.x (#45)

 - Refactor to use core + http for pouchdb to remove the need for
   leveldown in package-lock
 - As well as updating to a version of couch2pg that does the same
 - Adds a missing dependency that was being pulled in by dev deps

Gruntfile.js

@@ -6,12 +6,12 @@ module.exports = function(grunt) {
   grunt.initConfig({
     eslint: {
       options: {
-        configFile: ".eslintrc"
+        configFile: '.eslintrc'
       },
       src: [
-        "libs/**/*.js",
-        "tests/**/*.js",
-        "index.js"
+        'libs/**/*.js',
+        'tests/**/*.js',
+        'index.js'
       ]
     },
     mochaTest: {

libs/couch2pg.js

@@ -1,5 +1,5 @@
 const urlParser = require('url'),
-      PouchDB = require('pouchdb'),
+      PouchDB = require('./db'),
       couch2pg = require('couch2pg');
 
 // Removes credentials from couchdb url

libs/db.js

@@ -0,0 +1,4 @@
+const PouchDB = require('pouchdb-core');
+PouchDB.plugin(require('pouchdb-adapter-http'));
+
+module.exports = PouchDB;