No error reporting when given a malformed config file

[Zarkonnen]

Passing the following config file to the interpreter just causes it to run with zero test runs and no indication that anything's wrong.

{
"type":"interpreter-config",
"configurations":[
{
"settings": [
{
"driverOptions" "{
"host": "ondemand.saucelabs.com",
"port": 80
},
"browserOptions":{
"browserName":"firefox",
"username": "dhirajshinde1210",
"accessKey": "b0b27d7f-4446-4367-9176-af70abd46a5e"
}
}
],
"scripts":[
        "tests/*"
]
}
]
}