Resource Patch e2e test

[Szymongib]

Summary

We can add an e2e test for resource patch functionality.

The test should be fairly simple:

• Create Mattermost instance with resource patch specified for Deployment and Service.
• Assert that changes are applied to both resources.

Example patches can be found in unit tests https://github.com/mattermost/mattermost-operator/tree/master/apis/mattermost/v1beta1/testdata

[imskr]

I want to work on it

[Szymongib]

Awesome, thanks @imskr.