Bump sqlfluff from 0.6.9 to 0.7.0 in /src (#2378)

Bumps [sqlfluff](https://github.com/sqlfluff/sqlfluff) from 0.6.9 to 0.7.0.
- [Release notes](https://github.com/sqlfluff/sqlfluff/releases)
- [Changelog](https://github.com/sqlfluff/sqlfluff/blob/main/CHANGELOG.md)
- [Commits](sqlfluff/sqlfluff@0.6.9...0.7.0)

---
updated-dependencies:
- dependency-name: sqlfluff
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/requirements.txt

@@ -4,4 +4,4 @@ gunicorn==20.1.0
 pytest==6.2.5
 pytest-watch==4.2.0
 pytest-cov==3.0.0
-sqlfluff==0.6.9
+sqlfluff==0.7.0