Fix pretest error on windows

[p-v-d-Veeken]

Okay, so the entire scripts section of package.json is just one big clusterf--- on Windows.

First the test script failed because Windows can't into embedded quotes, I fixed it by creating a separate script which gets called from the pretest command. Then, the test script failed, because dark powers are forming and we are powerless to stop Them, I fixed that error by just typing into the terminal and seeing what stuck. Then the prepublish script failed and I decided I had enough for today.

So yeah, this PR will get you halfway through the scripts section of package.json on Windows. I will see what I can do with the prepublish script, but once again, no promises.

[svanschooten]

Please incorporate this in your next versions. Tests can not bet run on windows. 👍

[mbostock]

Some problems with this PR:

• Removing the -p breaks the mkdir command on OS X and Linux.
• Unintended removal of the eslint command.
• Unnecessary change to .gitignore.

I’ll submit a separate fix shortly.

[mbostock]

This change needs to be propagated to ~30 other D3 modules. Please let me know if it works, and then I’ll go ahead and re-apply this commit to the other modules. Thanks.

[p-v-d-Veeken]

@mbostock It doesn't work properly yet, see: #15

[mbostock]

Yep, I’m on it.