fix build bc freebsd annoying

Jenkinsfile

@@ -16,7 +16,7 @@ pipeline {
     stage('Python') {
       steps {
         sh '/usr/local/bin/python3.7 -m venv env'
-        sh 'env/bin/pip install -r requirements.txt'
+        sh 'env/bin/pip install -r requirements.ci.txt'
      }
     }
    }

requirements.ci.txt

@@ -0,0 +1,5 @@
+mypy==0.770
+mypy-extensions==0.4.3
+typed-ast==1.4.1
+typing-extensions==3.7.4.2
+websockets==8.1