➕ Change n8n-core dependency from dev to regular

packages/nodes-base/package.json

@@ -107,7 +107,6 @@
         "@types/xml2js": "^0.4.3",
         "gulp": "^4.0.0",
         "jest": "^23.6.0",
-        "n8n-core": "^0.8.0",
         "n8n-workflow": "^0.9.0",
         "ts-jest": "^23.10.1",
         "tslint": "^5.17.0",
@@ -123,6 +122,7 @@
         "lodash.get": "^4.4.2",
         "lodash.set": "^4.3.2",
         "lodash.unset": "^4.5.2",
+        "n8n-core": "^0.8.0",
         "nodemailer": "^5.1.1",
         "pdf-parse": "^1.1.1",
         "redis": "^2.8.0",