Windows support

[janluke]

First, thank you for this template, it's great!

Unfortunately, linting tasks currently depend on bash scripts. I don't know batch scripting, so I can't help int translating those scripts in batch. Nonetheless, I personally solved the problem as follows:

1. I added the bash executable bundled with "Git for Windows" to the PATH; precisely, I added "C:/Program Files/Git/bin" to the PATH;
2. In coursera.gradle, I modified the tasks for spotbugs, checkstyle and PMD by setting commandLine to just 'bash' and moving the path of the actual script to args. For example:

tasks.create(
            name: "${assignment.name}CheckStyle",
            type: Exec,
            dependsOn: [downlodCheckStyle, "${assignment.name}CodeAnalysisPrepare"]
    ) {
        // omitted
        commandLine "bash"    // <-- put bash here 
        args = ["$projectDir/.lift/bin/checkstyle", "-coursera"] + assignment.sources
    }

Not sure why the following didn't work: commandLine 'bash', "$projectDir/.lift/bin/checkstyle".

This is not a real solution, but it's something. I can open a PR with these changes (and instructions in the README) if you want.

[andsarr]

We could also try to create scripts for PowerShell.

[janluke]

Sure, but I have no time for that. What I'm proposing here is a workaround that enables most Windows users to easily use this template from today. If you already know powershell/batch and can write those scripts in minutes, writing them would be a better and definitive solution, of course :)

[andsarr]

I wrote the scripts using PowerShell but I haven't been able to test them properly. Maybe we should go with your suggestion in the meantime.

[janluke]

I opened a pull request.