Bump pytest-docker from 0.6.1 to 0.7.2 in /packages/service-library (#1327)

Bumps [pytest-docker](https://github.com/avast/pytest-docker) from 0.6.1 to 0.7.2.
- [Release notes](https://github.com/avast/pytest-docker/releases)
- [Changelog](https://github.com/avast/pytest-docker/blob/master/CHANGELOG.md)
- [Commits](avast/pytest-docker@v0.6.1...v0.7.2)

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

Author: dependabot-preview[bot]

packages/service-library/requirements/_test.txt

@@ -35,7 +35,7 @@ pyparsing==2.4.6          # via packaging
 pyrsistent==0.15.2        # via -r requirements/_base.txt (line 22), jsonschema
 pytest-aiohttp==0.3.0     # via -r requirements/_test.in (line 12)
 pytest-cov==2.8.1         # via -r requirements/_test.in (line 13)
-pytest-docker==0.6.1      # via -r requirements/_test.in (line 16)
+pytest-docker==0.7.2      # via -r requirements/_test.in (line 16)
 pytest-instafail==0.4.1.post0  # via -r requirements/_test.in (line 14)
 pytest-mock==2.0.0        # via -r requirements/_test.in (line 17)
 pytest-runner==5.2        # via -r requirements/_test.in (line 15)