truffle-config.js

module.exports = {
  networks: {
    development: {
      host: "127.0.0.1",
      port: 8545,
      network_id: "*", // Match any network id
      gas: 5000000
    }
  },
  compilers: {
    solc: {
      settings: {
        optimizer: {
          enabled: true, // Default: false
          runs: 200      // Default: 200
        },
      }
    }
  },
  build: {
    // Copy ./app/index.html (right hand side) to ./build/index.html.
    "index.html": "index.html",
    "app.js": [
      // Paths relative to "app" directory that should be
      // concatenated and processed during build.
      "javascripts/app.js"
    ],
    "app.css": [
      // Paths relative to "app" directory that should be
      // concatenated and processed during build.
      "stylesheets/app.css"
    ]
  }
};