Initial commit

- add the following files:
  + .gitignore => ignore poetry's and pyenv's artifacts
  + LICENSE.txt => MIT license as the project is scientific research
  + README.md => rough description of the project
  + poetry.lock
  + pyproject.toml
  + src/urban_meal_delivery/__init__.py => source code package
- use a "src" layout structure:
  + ensure that pytest runs the tests against a packaged and pip
    installed version of the source code, not the *.py files in the
    project directory
  + more info: https://hynek.me/articles/testing-packaging/

LICENSE.txt

@@ -0,0 +1,19 @@
+Copyright (c) 2020 Alexander Hess [alexander@webartifex.biz]
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.