Experimental TUI powered by Trogon

* sqlite-utils tui command if Trogon is installed, closes #545
* Documentation for trogon TUI
* Screenshot of TUI
* Ignore trogon mypy error
* only run flake8 on Python 3.8 or higher, closes #550

.github/workflows/publish.yml

@@ -26,7 +26,7 @@ jobs:
           ${{ runner.os }}-pip-
     - name: Install dependencies
       run: |
-        pip install -e '.[test]'
+        pip install -e '.[test,tui]'
     - name: Run tests
       run: |
         pytest

.github/workflows/test.yml

@@ -28,7 +28,7 @@ jobs:
           ${{ runner.os }}-pip-
     - name: Install dependencies
       run: |
-        pip install -e '.[test,mypy,flake8]'
+        pip install -e '.[test,mypy,flake8,tui]'
     - name: Optionally install numpy
       if: matrix.numpy == 1
       run: pip install numpy
@@ -44,7 +44,8 @@ jobs:
         pytest -v
     - name: run mypy
       run: mypy sqlite_utils tests
-    - name: run flake8
+    - name: run flake8 if Python 3.8 or higher
+      if: matrix.python-version >= 3.8
       run: flake8
     - name: Check formatting
       run: black . --check