Minor edits to labeler.py, use simplejson throughout

@subutai, @scottpurdy please review.
There was an line 114 error with the iterator previously. Replacing it with `labels["label"].values[values.indices] = 1` fixed the issue, but I made further edits to tighten up the code instead of the `moreThanT1` and `betweenT1AndT2` notation.

This change was included in this PR by mistake. I had made this edit, not pushed it, and then made the JSON edits on top of it. I should have pushed them as separate PRs.