Fixed upload overridng of files and added docker guide in docs.md

[noobed-max]

• closes #34
• fixed the upload overriding old files when the same key is used
• added the documentation for creating docker container in docs.md
• Also modified the tes.py to have single test , the reason being the test.py had a conflict with the updated upload endpoint code Unnecessary multiple tests different test cases created and requested multiple uploads , dialed that down to one or two and performing of update and delete is now performed on a single key rather than creating a new key each time.

[Tejas-ChandraShekarRaju]

I suggest you create a seperate PR for docs. Merging the bug fix I will have to review it carefully