Set poetry to python 3.6 and up and add a dev section to readme

Author: rs

README.md

@@ -38,3 +38,8 @@ An IP address must be in one of the whitelisted ranges for a response to be retu
 `NIPIO_BLACKLIST`: A space-separated list of description=ip blacklisted pairs. Example: `some_description=10.0.0.1 other_description=10.0.0.2`.
 
 This is useful if you're creating your own [Dockerfile](Dockerfile).
+
+## Development
+
+If you'd like to develop and hack with nip.io, then the easiest way is to install [Poetry](https://python-poetry.org/)
+and then run `./build.sh` which invokes Poetry. `./build.sh` will run linting and tests as well.

pyproject.toml

@@ -5,7 +5,7 @@ description = ""
 authors = ["rs <[email protected]>"]
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = "^3.6"
 
 [tool.poetry.dev-dependencies]
 pytest = "^5.2"