Avoid using shell scripting syntax for cross-platform support

[shalithasuranga]

Please consider changing the lines like these:

let output = runner.run('cd test-app && neu build')

We can write something like:

process.chdir('test-app');
let output = runner.run('neu build');

I think we can use runner.run() only for Neutralinojs commands to enable cross-platform support and better readability

Assignee: @pathange-s

[pathange-s]

Good, thanks you pointed it out. Actually, I didn't really think of this as I got a confirmation from you that, we will need to run the test suite only on Linux. Well, this seems to be a valid issue, I will submit a pull request for the same.