Step 2: Job page header component

What does this MR do?

Step 2 of rewriting job show page in vue.js: - Main MR is https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10987

• Adds fake data - to be deleted when we have backend
• Adds ci header reusable component based on UX mockups: https://gitlab-org.gitlab.io/gitlab-design/hosted/27724-large-build-logs-spec-previews/#artboard0 and pipeline header - to be used in both job and pipeline show pages
• Adds timeago tooltip shared component port of ruby helper
• Adds a layer for data validation between render function and API response

Screenshots (if relevant)

Currently renders:

User image to be added when https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10718 is merged

Does this MR meet the acceptance criteria?

• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together