Modernize extension

- update dependencies
- use tox for testing
- use type hints
- use pathlib and ipaddress from standard library instead of path and
  ipcalc
- fix Sphinx deprecation warnings

tests/root/conf.py

@@ -12,14 +12,14 @@
 #
 # All configuration values have a default; values that are commented out
 # serve to show the default.
-
-# import sys
-# import os
+import os
+import sys
+from typing import Dict
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-# sys.path.insert(0, os.path.abspath('..'))
+sys.path.insert(0, os.path.abspath(os.path.join("..", "..")))
 
 # -- General configuration ------------------------------------------------
 
@@ -47,7 +47,7 @@ master_doc = "index"
 
 # General information about the project.
 project = "Sphinxext IP Tests"
-copyright = "2016-2021, Jan Dittberner"
+copyright = "2016-2023, Jan Dittberner"
 author = "Jan Dittberner"
 
 # The version info for the project you're documenting, acts as replacement for
@@ -104,7 +104,6 @@ pygments_style = "sphinx"
 # If true, `todo` and `todoList` produce output, else they produce nothing.
 todo_include_todos = False
 
-
 # -- Options for HTML output ----------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
@@ -207,15 +206,15 @@ htmlhelp_basename = "SphinxextIPTestsdoc"
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
+latex_elements: Dict[str, str] = {
     # The paper size ('letterpaper' or 'a4paper').
-    #'papersize': 'letterpaper',
+    # 'papersize': 'letterpaper',
     # The font size ('10pt', '11pt' or '12pt').
-    #'pointsize': '10pt',
+    # 'pointsize': '10pt',
     # Additional stuff for the LaTeX preamble.
-    #'preamble': '',
+    # 'preamble': '',
     # Latex figure (float) alignment
-    #'figure_align': 'htbp',
+    # 'figure_align': 'htbp',
 }
 
 # Grouping the document tree into LaTeX files. List of tuples