General

• drop support for Python 2.7.x and Python < 3.7

Big fixes

• fix bug in output writing for montecarlo due to change in behaviour in spotpy
  (e2f695b)
• fix mistake in routing parameter used for "educated guess" as initial conditions
  (5345b1d)

Documentation

• add documentation build with sphinx
  (#3)
• add API reference
  (89dc0b)

Tests

• add GitHub workflow to run tests
  (#4)