feat: add new release commands to manage GitLab releases

[profclems]

New commands:

• glab release create <tag> [<files>...]
• glab release upload <tag> <files>...
• glab release view <tag>
• glab release download <tag> [<pattern>]
• glab release delete <tag>

Example output:

Example help:

$ glab release create -h

Create a new or update a GitLab Release for a repository.

If the release already exists, glab updates the release with the new info provided.

If a git tag specified does not yet exist, the release will automatically get created
from the latest state of the default branch and tagged with the specified tag name.
Use `--ref` to override this.
The `ref` can be a commit SHA, another tag name, or a branch name.
To fetch the new tag locally after the release, do `git fetch --tags origin`.

To create a release from an annotated git tag, first create one locally with
git, push the tag to GitLab, then run this command.

NB: Developer level access to the project is required to create a release.

USAGE
  glab release create <tag> [<files>...] [flags]

FLAGS
  -a, --assets JSON         JSON string representation of assets links (e.g. `--assets='[{"name": "Asset1", "url":"https://<domain>/some/location/1", "link_type": "other", "filepath": "path/to/file"}]')`
  -m, --milestone strings   The title of each milestone the release is associated with
  -n, --name string         The release name or title
  -N, --notes string        The release notes/description. You can use Markdown
  -F, --notes-file file     Read release notes file. Specify `-` as value to read from stdin
  -r, --ref string          If a tag specified doesn't exist, the release is created from ref and tagged with the specified tag name. It can be a commit SHA, another tag name, or a branch name.
  -D, --released-at date    The date when the release is/was ready. Defaults to the current datetime. Expected in ISO 8601 format (2019-03-15T08:00:00Z)

TODO:

• view: add metadata to rendered output
• view: add ability to view latest release for a repository
• create: add flags for metadata
• create: enable interactive flow
• create: accept a list of files for upload
• create: offer options to pre-populate release notes
  • Use commit messages as a template
  • Use merge request titles as a template
  • Use annotated git tag as template
• glab release upload command
• glab release download command
• glab release delete command

Fixes #366

[codecov]

Codecov Report

Merging #445 (f7a7342) into trunk (dbb7f2d) will decrease coverage by 0.32%.
The diff coverage is 39.17%.

@@            Coverage Diff             @@
##            trunk     #445      +/-   ##
==========================================
- Coverage   58.97%   58.65%   -0.33%     
==========================================
  Files          92       93       +1     
  Lines        6626     6687      +61     
==========================================
+ Hits         3908     3922      +14     
- Misses       2339     2384      +45     
- Partials      379      381       +2     

Impacted Files	Coverage Δ
commands/cmdutils/errors.go	0.00% <0.00%> (ø)
internal/glrepo/remote.go	97.29% <0.00%> (-2.71%)	⬇️
internal/glrepo/repo.go	85.29% <0.00%> (-9.28%)	⬇️
pkg/iostreams/icons.go	0.00% <0.00%> (ø)
pkg/iostreams/logger.go	0.00% <0.00%> (ø)
pkg/utils/utils.go	35.61% <0.00%> (-4.39%)	⬇️
cmd/glab/main.go	43.13% <62.06%> (+3.13%)	⬆️
pkg/iostreams/iostreams.go	38.54% <62.50%> (-0.83%)	⬇️
commands/release/list/release_list.go	73.07% <69.23%> (-3.12%)	⬇️
commands/api/http.go	81.08% <100.00%> (+3.53%)	⬆️
... and 3 more

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[profclems]

This is getting tougher than I expected esp with the upload of artifacts.

https://docs.gitlab.com/ce/api/releases/links.html#create-a-link

[clemsbot]

This PR has been automatically marked as stale because it has not had recent activity. This message is just a reminder for the author, reviewers and assignees.