Relax requirements and use more strict CI

Signed-off-by: Aleksei Stepanov <penguinolog@gmail.com>

(cherry picked from commit 288dae0)
Signed-off-by: Aleksei Stepanov <penguinolog@gmail.com>

Author: penguinolog

.travis.yml

@@ -75,14 +75,14 @@ jobs:
     install:
     - *upgrade_python_toolset
     - *install_deps
-    - pip install --upgrade "mypy >= 0.630"
+    - pip install --upgrade "mypy >= 0.670"
     script:
     - mypy --strict advanced_descriptors
   - <<: *static_analysis
     name: "PEP8"
     install:
     - *upgrade_python_toolset
-    - pip install --upgrade flake8
+    - pip install --upgrade flake8 flake8-bugbear
     script:
     - flake8
 

requirements.txt

@@ -1,2 +1,2 @@
 six >=1.10.0
-typing >= 3.6 ; python_version < "3.8"
+typing >= 3.6 ; python_version < "3.7"

tox.ini

@@ -112,6 +112,6 @@ commands =
 [testenv:mypy]
 usedevelop = False
 deps =
-    mypy>=0.630
+    mypy>=0.670
     -r{toxinidir}/CI_REQUIREMENTS.txt
 commands = mypy --strict advanced_descriptors