fix travis and deps

.travis.yml

@@ -48,8 +48,8 @@ install:
         tar -jxf ${PYPY_VERSION}.tar.bz2
         virtualenv --python="$PYPY_VERSION/bin/pypy3" "$HOME/virtualenvs/$PYPY_VERSION"
         source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
+        python -m pip install -U pip
       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

@@ -64,14 +64,15 @@ commands =
 [pinned]
 deps =
     -ctests/constraints.txt
-    #using cryptography-2.1.4 for test jobs to solve dependencies conflict on pip20.2>=
+    #using cryptography-2.1.4 to solve dependencies conflict on pip20.2>=
     cryptography==2.1.4
     cssselect==0.9.1
     itemadapter==0.1.0
     parsel==1.5.0
     Protego==0.1.15
     PyDispatcher==2.0.5
-    pyOpenSSL==16.2.0
+    #using pyOpenSSL<18.1 to solve dependencies conflict with mitmproxy on pip20.2>=
+    pyOpenSSL==18.0.0
     queuelib==1.4.2
     service_identity==16.0.0
     Twisted==17.9.0