Resolve code duplication in `commit_item.vue` and `last_commit.vue`
## Problem to solve
There is a bit of code duplication between these two components:
- [`app/assets/javascripts/diffs/components/commit_item.vue`](https://gitlab.com/gitlab-org/gitlab-ce/blob/8057ac7566dcf25682b2307d78488626f0ad64a6/app/assets/javascripts/diffs/components/commit_item.vue)
- [`app/assets/javascripts/repository/components/last_commit.vue`](https://gitlab.com/gitlab-org/gitlab-ce/blob/df3d9361e505db61de41b8e39516470d50c0e851/app/assets/javascripts/repository/components/last_commit.vue)
Let's try to fix this tech debt :muscle:
## Strategy
So that we don't introduce any regressions, it's probably wise to create a Jest snapshot test of the two components (or parent components).
issue