The docker build image cache seems to cause more problems and take
longer to load than it would take to build the image from scratch, so we
remove it.
Instead we make sure that we use the latest version of the 1.18 Golang
branch.
- `make mock`: generates all the mocks for testing.
- `mock-check`: generates all the mocks + checks if any *.go file changed.
- `make gen`: generates all the auto generated files (protos + mocks).
- Add `mock-check` to our CI
To make initial triage easier and nudge people into reading the
documentation and gathering information before submitting an issue, we
add three issue templates: bug reports, feature requests and "other".
