feat: Allow to recover from ENOTINHISTORY with a tag and handle detac…

…hed head repo

- Tag sha will now be used also if there is a gitHead in last release and it's not in the history
- Use `git merge-base` to determine if a commit is in history, allowing to use CI creating detached head repo
- Mention recovery solution by creating a version tag in `ENOTINHISTORY` and `ENOGITHEAD` error messages
- Do not mention branches containing missing commit in `ENOTINHISTORY` and `ENOGITHEAD` error messages as it's not available by default on most CI

fix: Always pass pluginConfig to plugins as a defined object

fix: Exit with 1 if unexpected error happens

feat: Retrieve version gitHead from git tags and unshallow the repo i…

…f necessary

Add several fixes and improvements in the identification of the last release gitHead:
- If there is no last release, unshallow the repo in order to retrieve all existing commits
- If git head is not present in last release, try to retrieve it from git tag with format ‘v\<version\>’ or ‘\<version\>’
- If the last release git head cannot be determined and  found in commit history, unshallow the repo and try again
- Throw a ENOGITHEAD error if the gitHead for the last release cannot be found in the npm metadata nor in the git tags, preventing to make release based on the all the commits in the repo as before
- Add integration test for the scenario with a packed repo from which `npm republish` fails to read the git head

Fix semantic-release#447, Fix semantic-release#393, Fix semantic-release#280, Fix semantic-release#276

fix(package): update @semantic-release/error to version 2.0.0

fix(package): Set minimum node version to 4 (semantic-release#442)

fix(package): update @semantic-release/last-release-npm to version 2.0.0

fix(package): update @semantic-release/commit-analyzer to version 3.0.1

fix(package): @semantic-release/[email protected]

This also introduces the new build leader detecation from https://github.com/semantic-release/travis-deploy-once/releases/tag/v2.0.0

fix(post): create git tag properly

refs/heads are for branches and refs/tags for tags.