Add static analysis for tests to toxfile

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py36, py37, py38, format, static, docs
+envlist = py36, py37, py38, format, static, static-tests, docs
 skip_missing_interpreters = true
 isolated_build = true
 
@@ -16,7 +16,7 @@ commands =
     pytest --cov={envsitepackagesdir}/keyosk --cov-config .coveragerc tests/ --cov-report term-missing
 
 [testenv:format]
-description = Enforce code formatting (pre-commit)
+description = Enforce file formatting (pre-commit)
 skip_install = true
 deps =
     pre-commit == 2.1.0
@@ -25,7 +25,6 @@ commands =
 
 [testenv:static]
 description = Static code analysis (mypy+pylint+bandit)
-skip_install = true
 ignore_errors = true
 deps =
     pylint == 2.3.1
@@ -37,6 +36,20 @@ commands =
     pylint keyosk --rcfile .pylintrc
     bandit --recursive keyosk
 
+[testenv:static-tests]
+description = Static code analysis for the tests (mypy+pylint+bandit)
+ignore_errors = true
+deps =
+    pytest == 5.3.5
+    pylint == 2.3.1
+    astroid == 2.2.5
+    mypy == 0.761
+    bandit == 1.6.2
+commands =
+    mypy tests --ignore-missing-imports --no-strict-optional
+    pylint tests --rcfile .pylintrc
+    bandit --recursive tests --skip B101
+
 [testenv:docs]
 description = Build documentation (sphinx)
 deps =