Updated travis to use pipenv

.travis.yml

@@ -22,14 +22,17 @@ before_install:
 
 install:
 # Python
-- pip freeze
-- pip install -r monkey/monkey_island/requirements.txt  # for unit tests
-- pip install black==20.8b1 flake8==3.9.0 pytest pytest-cov isort==5.8.0 # for next stages
-- pip install coverage  # for code coverage
-- pip install -r monkey/infection_monkey/requirements.txt  # for unit tests
-- pip install pipdeptree
-# Fail builds on possible conflicting dependencies.
-- pipdeptree --warn fail
+- pip install pipenv
+# Install requirements as they are needed by UT's
+- pushd monkey/monkey_island
+- pipenv install
+- popd
+- pushd monkey/infection_monkey
+- pipenv install
+- popd
+- pipenv install black==20.8b1 flake8==3.9.0 pytest pytest-cov isort==5.8.0 # for next stages
+- pipenv install coverage  # for code coverage
+
 
 # node + npm + eslint
 - node --version