It's mentioned on package that there is no dependency :

But after installation it gave me error :
├── UNMET PEER DEPENDENCY react@15.4.2
├── UNMET PEER DEPENDENCY socket.io-client@2.0.3
└── socket.io-react@1.2.0

While if you see my package json :
"react": "15.4.2",
"socket.io-client": "2.0.3",
"socket.io-react": "1.2.0",

All the required packages are already there. Please test your plugin once before publishing.