Optimize TravisCI Build Time

[RishabhJain2018]

Issue

Currently, the build time for our travis-ci build is ~22 minutes: https://app.travis-ci.com/github/Cloud-CV/EvalAI/builds/274731262?serverType=git

Deliverable

Optimize the Travis CI script or the Dockerfiles to reduce the build time.

[Zahed-Riyaz]

Hi, @RishabhJain2018 I would like to work on this issue

[RishabhJain2018]

:) Sure!

[lazyperson1020]

Can I work on this? @RishabhJain2018 as I don't have any other issue assigned.

[RishabhJain2018]

Hey @lazyperson1020 , You can take this one: #4544