Add scrum methods / information

[Lakritzator]

See: https://docs.atlassian.com/greenhopper/REST/cloud/#agile/1.0/board-getBoard

This doesn't work with 6.x

[Lakritzator]

The REST URI for the agile information is a bit different: /rest/agile/1.0/

[Lakritzator]

Should be in the Agile "domain", _jiraApi.Agile.GetBoardsAsync()

[Lakritzator]

• [x] Get all boards
• [x] Create board
• [x] Get board
• [x] Delete board
• [x] Get issues for backlog
• [x] Get all sprints for board
• [ ] Get projects for board
• [x] Get issues for sprint
• [ ] Get epics for board
• [ ] Get issues for epic
• [ ] Get issues without epic

The Agile API has different information in the issue details: Returns a single issue, for a given issue Id or issue key. Issues returned from this resource include Agile fields, like sprint, closedSprints, flagged, and epic.

Sprints:

• [ ] Create
• [ ] Get
• [ ] Update
• [ ] Move issues to
• [ ] Delete

[Lakritzator]

Get boards: /rest/agile/1.0/board -> Get sprints: /rest/agile/1.0/board/2/sprint -> Get sprint issues: /rest/agile/1.0/board/2/sprint/10/issue

[Lakritzator]

Functionality is not available with Version < 7 of Jira Server