feat(evergreen): use evergreen flag when running tests

this will pass the option down to `mongodb-download-url` and enable detection of Linux Distributions

Author: Jessica Lord

.evg.yml

@@ -28,7 +28,8 @@ functions:
           [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
 
           npm install
-          MONGODB_VERSION=${VERSION} MONGODB_ENVIRONMENT=${TOPOLOGY} npm test
+          MONGODB_VERSION=${VERSION} MONGODB_ENVIRONMENT=${TOPOLOGY}
+          mongodb-test-runner --evergreen -t 60000 test/tests/functional
 
 pre:
     - func: "fetch source"