Stricter TypeScript configuration

tsconfig.json

{
  "compilerOptions": {
      "target":"es6",
      "module": "commonjs",
      "declaration": true,
      "sourceMap": true,
      "outDir": "./lib",
      "rootDir": "./src",
      "types": [
        "node"
      ],
      "skipLibCheck": true,
      "skipDefaultLibCheck": true,
      "resolveJsonModule": true,
      "experimentalDecorators": true,
      "emitDecoratorMetadata": true,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "forceConsistentCasingInFileNames": true,
      "noImplicitReturns": true,
      "strict": true,
      "noUnusedLocals": true
  },
  "include": [
      "src/**/*"
  ]
}