travis and deps

.travis.yml

@@ -40,6 +40,8 @@ matrix:
     - env: TOXENV=asyncio
       python: 3.8
       dist: bionic
+before_install:
+  - pip install -U pip
 install:
   - |
       if [[ ! -z "$PYPY_VERSION" ]]; then
@@ -49,7 +51,6 @@ install:
         virtualenv --python="$PYPY_VERSION/bin/pypy3" "$HOME/virtualenvs/$PYPY_VERSION"
         source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
       fi
-  - pip install --upgrade pip
   - pip install -U tox twine wheel codecov
 
 script: tox

tox.ini

@@ -64,8 +64,8 @@ commands =
 [pinned]
 deps =
     -ctests/constraints.txt
-    #using cryptography-3.1 to solve dependencies conflict on pip20.2>=
-    cryptography==3.1
+    #using cryptography-2.3.1 to solve dependencies conflict on pip20.2>=
+    cryptography==2.3.1
     cssselect==0.9.1
     itemadapter==0.1.0
     parsel==1.5.0