feat(mypy): Add basic configuration file for Mypy

- add basic mypy config
- update mypy command inside tox config
- set hg to ignore mypy_cache folder
- add just enough type inside schema.py to please mypy

.hgignore

@@ -2,3 +2,4 @@ dist
 .tox/
 cubicweb_intranet.egg-info/
 test/data/database
+.mypy_cache/

cubicweb_intranet/schema.py

@@ -13,6 +13,7 @@ from cubicweb_card.schema import Card
 from cubicweb_blog.schema import BlogEntry
 from cubicweb_file.schema import File
 from cubicweb_link.schema import Link
+from typing import Tuple
 
 PERMISSIONS = {
     "read": (
@@ -46,7 +47,15 @@ class interested_in(RelationDefinition):
     object = "Event"
 
 
-BASETYPES = ("Card", "BlogEntry", "File", "Event", "Link", "Task", "Book")
+BASETYPES: Tuple[str, ...] = (
+    "Card",
+    "BlogEntry",
+    "File",
+    "Event",
+    "Link",
+    "Task",
+    "Book",
+)
 if "VersionedFile" in context.defined:
     BASETYPES += ("VersionedFile",)
     from cubicweb_vcsfile.schema import VersionedFile, VersionContent

mypy.ini

+[mypy]
+ignore_missing_imports = True
+show_error_codes = True
+exclude = cubicweb_intranet/migration

tox.ini

@@ -37,7 +37,7 @@ commands =
 [testenv:mypy]
 deps =
   mypy >= 0.761
-commands = mypy --ignore-missing-imports cubicweb_intranet
+commands = mypy {posargs} cubicweb_intranet
 
 [testenv:black]
 basepython = python3