PYTHON-2193 Update install dependencies for OCSP tests

Author: ShaneHarvey

.evergreen/config.yml

@@ -699,7 +699,7 @@ functions:
         script: |
           cd ${DRIVERS_TOOLS}/.evergreen/ocsp
           /opt/mongodbtoolchain/v3/bin/python3 -m venv ./venv
-          ./venv/bin/pip3 install asn1crypto oscrypto bottle
+          ./venv/bin/pip3 install -r ${DRIVERS_TOOLS}/.evergreen/ocsp/mock-ocsp-responder-requirements.txt
     - command: shell.exec
       params:
         background: true
@@ -717,7 +717,7 @@ functions:
         script: |
           cd ${DRIVERS_TOOLS}/.evergreen/ocsp
           /opt/mongodbtoolchain/v3/bin/python3 -m venv ./venv
-          ./venv/bin/pip3 install asn1crypto oscrypto bottle
+          ./venv/bin/pip3 install -r ${DRIVERS_TOOLS}/.evergreen/ocsp/mock-ocsp-responder-requirements.txt
     - command: shell.exec
       params:
         background: true