Nock-exec is a [`child_process.exec`](nodejs.org/api/child_process.html#child_process_child_process_exec_command_options_callback) mocking library for Node.js

# Usage
In your test you can write:
```js
var nockExec = require('nock-exec');
nockExec('myapp').err('some error').reply(0, 'This command was mocked');
```

This means that any call in the form
```js
var exec = require('child_process').exec;
exec('myapp', function(error, stdout, stderr) {
   console.log('stdout: ' + stdout);
   console.log('stderr: ' + stderr);
   if (error !== null) {
     console.log('exec error: ' + error);
   }
});
```
will produce this output:
```
stdout: This command was mocked
stderr: some error
```