Update the deployment with correct model names, requirements and image

[hemajv]

For our upcoming talk at DevConf we plan to use this as part of our demo. There are few things which are outdated in the current deployment and this PR addresses them as follows:

• Updating the requirements.txt with necessary packages and versions
• Updating the app/app.py to include additional evaluation metrics such as ROUGE score
• Some of the IBM BAM model names have changed and hence these have been updated in app/app.py
• All the above mentioned changes have been pushed to a new docker image docker.io/hemaveeradhi/api-docs:v0.2.0 which has also been updated to be used in the deployment.yaml

cc @suppathak

[RobotSail]

LGTM

[aakankshaduggal]

Lgtm!