windows support

[mythmon]

Fixes #90.

• disable autocrlf
• test on windows
• cross-spawn
• rimraf
• use cross-env to run mocha
• fix tests with posix paths
• one less op
• mostly posix
• fix data loader and config tests
• more tests
• all tests passing

[mythmon]

I'm enabling auto merge on this; but it won't merge until our CI configuration change to look for the newly added CI jobs instead of the old one.

[mbostock]

What does this do?

[mythmon]

fail-fast: true (the default) means that if any CI job fails, the rest are immediately cancelled. fail-fast: false lets them all run to completion. true saves on CI time, false leads to easier debugging.

[mythmon]

We need to add rimraf to the template package.json's