Include more documentation for testing provided example

[sprice]

I'm trying to test the provided Express example and I've filled out config_test.json with what I think are all correct details. When hitting the provided example url I'm getting

Cannot send payment: {"TIMESTAMP":"2014-01-06T22:02:45Z","CORRELATIONID":"2c4dd53d28345","ACK":"Failure","VERSION":"98","BUILD":"9138168","L_ERRORCODE0":"10002","L_SHORTMESSAGE0":"Security error","L_LONGMESSAGE0":"Security header is not valid","L_SEVERITYCODE0":"Error"}

[mpneuried]

Sorry, it took a long time to find the necessary time. If this Issue is allready interresting for you please send me your filled out config.json, but without the password and signature.

Witch provider you are trying to use? It looks like your using a wrong signature. The module itself posts this Data raw to the Paypal Endpoints.

My working config looks like:

{
    "serverDefaultPort": 8889,
    "paypal": {
        "userid": "[ YOUR USER MAIL ]",
        "password": "[ YOUR PASSWORD ]",
        "signature": "[ YOUR SIGNATURE ]",
        "receiver_email": "[ YOUR RECEIVER MAIL ]",
        "localcode": "DE"
    },
    "paypalipn":{
        "host": "www.webmart.de",
        "port": 80,
        "listenport": 8888,
        "secure": true,
        "receiverPath": "/ipntest/paypal",
        "ppReturnPath": "/cgi-bin/webscr",
        "receiver_email": "[ YOUR RECEIVER MAIL ]"
    }
}