Support offline mode within datree docker image

[adifayer]

Describe the solution you'd like
Provide a solution for running datree in offline mode within Datree's docker image

[adityassharma-ss]

I think to run it in offline mode you can first pull the datree docker image locally using docker pull datreeio/datree & then create a new container specifying the --offline flag i.e., docker run -it --offline datreeio/datree