Devtools scripts: Relative paths from root

[BenSchZA]

I believe @nolash is working on this already, but all scripts should ideally reference paths from the project root.

As an example, the quick_setup_script script has to be run from the devtools folder:

python: can't open file 'manage.py': [Errno 2] No such file or directory
./devtools/quick_setup_script.sh: line 49: cd: ../eth_worker/: No such file or directory
  FAILED: No config file 'alembic.ini' found, or file has no '[alembic]' section```

[nolash]

@BenSchZA Thanks for this. This work however is not currently in progress, should be taken as one task. Should also address side-effects in package inclusions. Probably those are two separate issues though.