Promisify evm_increateTime

timeTravel.js

const timeTravel = function (time) {
  return new Promise((resolve, reject) => {
    web3.currentProvider.sendAsync({
      jsonrpc: "2.0",
      method: "evm_increaseTime",
      params: [time], // 86400 is num seconds in day
      id: new Date().getTime()
    }, (err, result) => {
      if(err){ return reject(err) }
      return resolve(result)
    });
  })
}