Readability fixes

[nrayyagari]

1. Remove unused copy module from main.py
2. Adjusting Dockerfile for enhanced readability and following regular Dockerfile practices
3. Adding try except block for main.py to catch any errors in execution
4. Correcting typo in shebang for better readability

@madron: Please do check above changes, some of them wont impact functionality but would improve readability for a regular user