Update travis-pip and tox deps conflict for pip20.2

.travis.yml

@@ -49,6 +49,7 @@ install:
         virtualenv --python="$PYPY_VERSION/bin/pypy3" "$HOME/virtualenvs/$PYPY_VERSION"
         source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
       fi
+  - python -m pip install --upgrade pip #force travis to use newest version of pip
   - pip install -U tox twine wheel codecov
 
 script: tox

tox.ini

@@ -64,7 +64,8 @@ commands =
 [pinned]
 deps =
     -ctests/constraints.txt
-    cryptography==2.0
+    #using cryptography-2.1.4 for test jobs to solve dependencies conflict on pip20.2>=
+    cryptography==2.1.4
     cssselect==0.9.1
     itemadapter==0.1.0
     parsel==1.5.0