starting changes for custom template

[atifsyedali]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Allow specifying a custom template by pointing to a template file.

• What is the current behavior? (You can also link to an open issue here)

Doesn't allow custom templates for copyright headers.

• What is the new behavior (if this is a feature change)?

Allows custom templates for copyright headers.

• Other information:

As per #4 (comment) Implemented the input arguments and test cases -- but it doesn't work :\