Instrument

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* drop Python 2.7 support
* `all`, `each` and `first` can now be used directly as decorators
* add `logging_metric` & `stderr_metric` outputs
* move outputs to `instrument.output` subpackage
* split `instrument.output.numpy` to `plot` & `table` modules
* instrumenter renames: `reducer`, `producer`, `function`, `all`, `first`, `each`
* move `print_metric` and `make_multi_metric` to `instrument.output`

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* rename project to ``instrument`` from ``measure_it``
* update to modern tooling: pytest, pipenv, etc..
* improved testing: tox, travis
* fix to work with newer versions of statsd, including its django support

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* add default_metric
* add make_multi_metric
* add TableMetric and PlotMetric, based on numpy
* add CSVDirMetric and CSVFileMetric
* measure_block supports user-supplied count

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* add measure_first, measure_produce, measure_func, measure_block
* rename measure to measure_iter and deprecate old name

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* add measure_reduce

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Initial release