tr test case is skipped (need to support right-hand side of pipes)

[nfischer]

I'm not sure why this test is skipped, it looks like it's been skipped since the initial commit. We can probably just enable it, but care should be taken to make sure it works.

[nfischer]

Hmm this seems to be related to this TODO:

shelljs-exec-proxy/index.js

Line 55 in b809b82

// TODO(nate): put hooks in ShellString so that I can Proxy-ify it to allow new

This might require changes on the shelljs side first.

[nfischer]

Here's the full comment for better readability (the issue has to do with the right-hand side of pipes).

shelljs-exec-proxy/index.js

Lines 55 to 56 in b809b82

	// TODO(nate): put hooks in ShellString so that I can Proxy-ify it to allow new
	// commands on the right hand side of pipes