Fabric Independence - rewrite core SSH and remote functionality directly over paramiko

[kabirbaidhya]

• Rewrite the core ssh and remote execution using paramiko.
  • [x] Add basic SFTP functions like get, put, read, write directly over paramiko #98
  • [x] Rewrite logic with basic ssh read and write sftp operations using the new ssh module w/o relying on fabric #101
  • [x] Ability to upload local directory to the remote host #105
  • [x] Better file/directory upload API with progress #110
  • [ ] Better file/directory download API with progress
  • [ ] Error handling for run function.
• Get rid of Fabric
  • [ ] Get rid of fabric's context managers
  • [ ] Get rid of fabric's run operation to run remote commands
  • [ ] Get rid of get, put and upload apis to transfer files.
• Refactor all remote execution code.
• Integration/Regression Tests:
  • [x] Write more integration tests for the api/core functions #87
  • [ ] Write end to end tests for whole deployment process.
  • [ ] Containerized SSHD for running E2E/integration tests for deployments