* Added function to get all users from a specific project

* Added function to get all users from a specific project - Pull Request changes

* Added function to get all users from a specific project

* added endpoint for retrieving subgroups for a group

* gofmt

* moved subgroup into the groups object

* removed concept of subgroup and using group instead

Not all methods are implemented, only the ones which I needed and verified.

* Snippet: add Explore API call

See https://docs.gitlab.com/ce/api/snippets.html#explore-all-public-snippets

* Snippet: add missing raw_url property

* Some renames for consistency

* updated Settings and UpdateSettingsOptions

* Add release_description to tag

* Add Create/Update/Get Jenkins Service

* add support for paginate options in list tag

this may change in the future with: https://gitlab.com/gitlab-org/gitlab-ee/issues/2004

Ref: https://docs.gitlab.com/ce/api/merge_requests.html

I tweaked it just a little to make it fit in a bit better with the rest of the code and fix a few lint warnings.

Thanks again for your PR @zaquestion!

* Add missing fields to `Namespace` struct

* Add support for namespaces: get

* Add support for `start_branch` in `CreateCommitOptions`

* BREAKING: add support for `from` in `GetUserActivities`

* Add missing fields to `Namespace` struct

* Add support for namespaces: get

* Add support for `start_branch` in `CreateCommitOptions`

* Add missing fields to `Namespace` struct

* Add support for namespaces: get

* Add support for labels: subscribeTo / unsubscribeFrom

* Add support for protected branches: ListProtectedBranches

* Add support for ProtectedBranches: Get

* Add support for protected branches: protect repository branch

* Add support for protected branches: unprotect repository branch

* Update README

MergeCommitShaSHA is renamed to MergeCommitSHA

Fixes https://github.com/xanzy/go-gitlab/issues/285

* Add support for merge request: create todo

see https://docs.gitlab.com/ce/api/merge_requests.html#create-a-todo

* Add support for merge request: get diff versions

see https://docs.gitlab.com/ce/api/merge_requests.html#subscribe-to-a-merge-request
and https://docs.gitlab.com/ce/api/merge_requests.html#unsubscribe-from-a-merge-request

* update UpdateIssue (#6)

* Updated Issue struct and MergeRequest struct (#7)

see https://docs.gitlab.com/ce/api/merge_requests.html#cancel-merge-when-pipeline-succeeds

According to the API documentation, a `201 OK` will be returned
upon success for the block / unblock user call.

See https://docs.gitlab.com/ce/api/users.html#block-user

This commit adds the following badges

- the project License
- go report card score
- number of Projects go-gitlab is used by (sourced fom sourcegraph)
- number of open Github issues

It also rearranges them slightly.
Signed-off-by: Gavin-John Noonan <mail@gjnoonan.co.uk>