Bump version to 2.1.0

Bump version to 2.0.2

Improvements

============
* Only log online_clients if there are any (6e40555)

Bugs
====
* Handle connected clients on unexpected shutdown correctly (1ef4a3b)

Internal
========
* Use pylama for stylechecks (ae13390),
fix error introduced by that (f878fef)
* Add Pipfile (a019278)
* Remove extra lines after encoding header (5ea2f6a)
* Lock dependencies in requirements.txt and testing_requirements.txt (187ae0a)
* Lock pendulum to version 1.5.1 for now because 2.0.0 contains
incompatible changes (a019278, e92f5ea)

Refactor it!

============

Changes
=======
* Refactor and cleanup of tsstats.log (08b4e06, da2b773, a084101, 91a9b8e)
* InvalidLog is not raised anymore, as there's nothing you can do about
(caff246)

Fixes
=====
* Relative timestamp human test was bound to the year 2017 (ab68f57)

Internal

========
* Add pendulum requirement to setup.py (3067c22) and testing_requirements.txt
(7dbd37b)

Improvements

============
* Optionally (new default) show last online time relative (72a4fbe)

Internal
========
* Switch from plain datetime to pendulum for datetime handling (65a8379)

Improvements

============
* Add space between nick and clid in repr of Client (11acf9f)

Documentation
=============
* Provide a working example in README.md, which is not triggering
shell-expansion (fec833d)

Bugs
====
* UnicodeEncodeError in debug mode with Python 2 (992d35e)

Internal
========
* Fix Clients.__add__ not using identmap (f209573)
* Close log files after parsing -> possible performance improvement (a4c04e3)
* Finally sign tags and releases

1.4.2

Internal
========
* setup.py now includes README.rst as long_description (shown on PyPi)
(cbf7000)

Documentation
=============
* Refactoring, cleaning up README and updating standards to new
Sphinx-version (ef5894b)

1.4.1

Bugs
====
* Fixed possibly wrong identifier when using IdentMap (#18, 1bc555d)

Internal
========
* New testcase for #18 (683f9b9)

1.4.0

Feature
=======
* Add ability to pass a directory for --log option (#17)

Internal
========
* Log execution time (e4212f2 + 0081ac9)
* PEP8 Fix (270b20d)