Added sql linter

Co-authored-by: Felix Delattre <fd@gfz-potsdam.de>
4 jobs for feature/ci-add-sql-linter in 59 seconds (queued for 2 seconds)
Name Stage Failure
failed
linter Test
WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
WARNING: You are using pip version 21.2.4; however, version 21.3.1 is available.
You should consider upgrading via the '/usr/local/bin/python -m pip install --upgrade pip' command.
$ sqlfluff lint --dialect postgres
== [/builds/dynamicexposure/openbuildingmap/database-obmbuildings/migrations/00003_add_column_geometry.sql] FAIL
L: 2 | P: 45 | L010 | Keywords must be consistently upper case.
All Finished 📜 🎉!
Cleaning up file based variables
ERROR: Job failed: exit code 1