Migrate openrouteservie-py to the year 2021

[MichaelsJP]

• Adjust conda publish action to pick up the system wide package version.
• integrate poetry
• integrate tox
• Add Readme instructions to use the new tools
• Move to codecov. coveralls has a really buggy branch coverage detection. this makes coverage testing a pain. codecov seems to fit.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (master@1d7b7e6). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             master       #60   +/-   ##
==========================================
  Coverage          ?   100.00%           
==========================================
  Files             ?        12           
  Lines             ?       525           
  Branches          ?         0           
==========================================
  Hits              ?       525           
  Misses            ?         0           
  Partials          ?         0           

Flag	Coverage Δ
unittests	100.00% <0.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1d7b7e6...93021be. Read the comment docs.

[TheGreatRefrigerator]

Looks good.

In general, i would suggest to cleanup feature branch commits by rebasing to keep the commits to review to a minimum and increase reviewability by a lot.

E.g. changes to pyproject.toml contain different mail addresses in the beginning that get fixed in further commits.
If it is an important change having information about mistakes being made that should be avoided in the future it can be kept to be accessible by git blame or PyCharm Annotations.

But especially typo fixes can be amended to a previous fitting commit to reduce the commit load for a PR.

In a similar manner, i often restructure my commits with changes to the same file into one if feasible.

Just as suggestion