Pandas, scikit not being installed

I am very new to travis and in the process of implementing it in collaborative coding.
I have setup my .travis.yml file to install some packages as seen below.
install:
– pip install -r requirements.txt

while the requirements.txt file contains
numpy==1.14.2
pytest==4.5.0
pandas==1.1.5
scipy==1.4.1

However pandas and scipy are never installed.
Is there something I can do to rectify this?
Is there something

Most probably, these specific versions are incompatible with the Python version you’re using.

Need to see the build to say for sure.

Can I look at your .travis.yml @rolawsongh7?