Add cookie parser to echo the value of cookies in the response. Also works for signed cookies.

[mendhak]

To sign a cookie, generate a value using

SIGNED_COOKIE=$(node -e "var crypto = require('crypto');

function sign(val, secret){
  return val + '.' + crypto
    .createHmac('sha256', secret)
    .update(val)
    .digest('base64')
    .replace(/=+$/, '');
};

console.log(sign('my-value','examplekey'));")

Start the container with the same secret key

docker run -d --rm -e COOKIE_SECRET=examplekey --name http-echo-tests -p 8080:8080 -p 8443:8443 -t mendhak/http-https-echo:testing

Then send it in the header like so

curl -s http://localhost:8080/ -H "Cookie: mysigned=s:${SIGNED_COOKIE}"

Issue #93