In development mode while dealing with lot of transactions handling Metamask pop-ups are pain. To avoid that we can create and sign raw transactions.

SkipMetamask.js

var Web3 = require('web3');
const Tx = require('ethereumjs-tx')

var web3 = new Web3(Web3.givenProvider || "ws://localhost:8546");

// the address that will send the test transaction
const addressFrom = '0xDFf7787B927c0F03C3a8a49aF6726a074923663c'
//private key of above address
const privKey = 'replace_me'
//address to receive ether
const addressTo = '0x002E28950558Fbede1A9675Cb113F0BD20912019'

//Return number of transactions sent so far from the given address
function getTransactionCount(address) {
    return new Promise(function(resolve, reject) {
        web3.eth.getTransactionCount(address)
        .then((txCount) => {
            resolve(txCount)
        })
        .catch((error) => {
            reject(error)
        })
    })
}

//send raw transaction (sendSignedTransaction in web3.js v1.0.0)
function sendTransaction(txData) {
    return new Promise(function(resolve, reject) {
        const privateKeyHex = new Buffer(privKey, 'hex')
        const transaction = new Tx(txData)
        transaction.sign(privateKeyHex)
        const serializedTx = transaction.serialize().toString('hex')
        
        web3.eth.sendSignedTransaction('0x' + serializedTx)
        .on('transactionHash', function(hash){
            console.log('transaction hash ', hash)
        })
        .on('receipt', function(receipt){
            console.log('transaction receipt ', receipt)
        })
        .on('confirmation', function(confirmationNumber, receipt){
            console.log('confirmationNumber ', confirmationNumber)
            resolve(receipt) })
        .on('error', function(error) {
            reject(error)
        }); // If a out of gas error, the second parameter is the receipt.
        
    })
}

//create raw transaction data and fire
getTransactionCount(addressFrom)
.then((txCount => {
    // construct the transaction data
    const txData = {
        nonce: web3.utils.toHex(txCount),
        gasLimit: web3.utils.toHex(250000),
        gasPrice: web3.utils.toHex(10e9), // 10 Gwei
        to: addressTo, 
        from: addressFrom,
        value: web3.utils.toHex(web3.utils.toWei('0.1', 'ether'))
    }

    sendTransaction(txData)
    .then((response) => {
        console.log('transaction sent ', response)
    })
    .catch((error) => {
        console.log('transaction failed ', error)
    })
}))
.catch((error) => {
    console.log('transaction count failed ', error)
})