Documentaion and sanity testing issues

[maaquib]

• Running python ./ts_scripts/install_from_src.py && python ./torchserve_sanity.py on a fresh EC2 instance (Ubuntu 18.04) throws exception due to missing dependencies not installed in install_from_src.py

## In directory: /home/ubuntu/serve | Executing command: pylint -rn --rcfile=./ts/tests/pylintrc ts/.
sh: 1: pylint: not found
...
## TorchServe Linting Failed !

• We should verify that the versions of Java, Python and Pip are correct before running ts_scripts/install_from_src.py

• Looking at the readme it is not clear right now whether Install Java 11 and Install python pre-requisite packages are also prerequisites for Install TorchServe for development

• Verify that re-running ts_scripts/install_from_src.py and other scripts multiple times doesn't break the tests

[chauhang]

Additionally please see: #797 (comment)

[codinnvrends]

@maaquib Could you please share logs for this. Assuming these are not EC2 DLAMI instances.
NOTE Our observation, on non-DLAMI nodes, the python site-packages are not accessible and hence our dependencies gets installed under ~/.local/....

[codinnvrends]

Additionally please see: #797 (comment)

Commented on #797

[maaquib]

@maaquib Could you please share logs for this. Assuming these are not EC2 DLAMI instances.
NOTE Our observation, on non-DLAMI nodes, the python site-packages are not accessible and hence our dependencies gets installed under ~/.local/....

This was a barebones EC2 instance, not DL AMI

[harshbafna]

Documentation has been updated as part of #836. Closing.