Jupyter support, Python 3.7, upgraded dependencies, Tutorial notebook

[OriHoch]

Converted the tutorial to a Jupyter notebook, a familiar environment for data scientists, allowing to quickly play around with Dataflows. It's rendered by GitHub: https://github.com/OriHoch/dataflows/blob/printer-support-jupyter-notebook/TUTORIAL.ipynb

Also, added more detailed installation instructions to the tutorial for more robust, OS agnostic installation.

Modified printer processor to support html table output for Jupyter and other minor improvements.

[OriHoch]

thanks @akariv fixed

[OriHoch]

@akariv added support for Python 3.7, upgraded datapackage, cchardet and plyvel

[OriHoch]

@akariv fixed

[coveralls]

Pull Request Test Coverage Report for Build 119

• 22 of 28 (78.57%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.2%) to 77.984%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
dataflows/processors/printer.py	22	28	78.57%
<!--	Total:	22	28	78.57%	-->

Files with Coverage Reduction	New Missed Lines	%
dataflows/processors/printer.py	1	86.0%
<!--	Total:	1		-->

Totals
Change from base Build 119:	-0.2%
Covered Lines:	1091
Relevant Lines:	1399

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 128

• 22 of 31 (70.97%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.3%) to 77.873%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
dataflows/processors/printer.py	22	31	70.97%
<!--	Total:	22	31	70.97%	-->

Totals
Change from base Build 119:	-0.3%
Covered Lines:	1091
Relevant Lines:	1401

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💛 - Coveralls