Added linting shell scripts

setup.cfg

@@ -0,0 +1,14 @@
+[metadata]
+description-file = README.md
+
+[isort]
+force_single_line=True
+known_first_party=neukit
+line_length=80
+profile=black
+
+[flake8]
+# imported but unused in __init__.py, that's ok.
+per-file-ignores=*__init__.py:F401
+ignore=E203,W503,W605,F632,E266,E731,E712,E741
+max-line-length=80

shell/format.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+isort --sl neukit app.py
+black --line-length 80 neukit app.py
+flake8 neukit app.py

shell/lint.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+isort --check --sl -c neukit app.py
+if ! [ $? -eq 0 ]
+then
+  echo "Please run \"sh shell/format.sh\" to format the code."
+  exit 1
+fi
+echo "no issues with isort"
+flake8 neukit app.py
+if ! [ $? -eq 0 ]
+then
+  echo "Please fix the code style issue."
+  exit 1
+fi
+echo "no issues with flake8"
+black --check --line-length 80 neukit app.py
+if ! [ $? -eq 0 ]
+then
+  echo "Please run \"sh shell/format.sh\" to format the code."
+    exit 1
+fi
+echo "no issues with black"
+echo "linting success!"