Travis CI: Run pytest on the FTP files

Author: cclauss

.travis.yml

@@ -12,8 +12,6 @@ script:
   - pytest . --doctest-modules
       --ignore=data_structures/stacks/balanced_parentheses.py
       --ignore=data_structures/stacks/infix_to_postfix_conversion.py
-      --ignore=file_transfer_protocol/ftp_send_receive.py
-      --ignore=file_transfer_protocol/ftp_client_server.py
       --ignore=machine_learning/linear_regression.py
       --ignore=machine_learning/perceptron.py
       --ignore=machine_learning/random_forest_classification/random_forest_classification.py