Update a screenshot marker

curl "https://api.phrase.com/v2/projects/:project_id/screenshots/:screenshot_id/markers" \
  -u USERNAME_OR_ACCESS_TOKEN \
  -X PATCH \
  -d '{"branch":"my-feature-branch", "key_id":"abcd1234abcd1234abcd1234abcd1234","presentation":"{ \"x\": 100, \"y\": 100, \"w\": 100, \"h\": 100 }"}' \
  -H 'Content-Type: application/json'

{
  "id": "d2e056aa9e70b01121f41693e344f5ee",
  "presentation": {
    "x": 10,
    "y": 10,
    "w": 10,
    "h": 10
  },
  "presentation_type": "default",
  "created_at": "2015-01-28T09:52:53Z",
  "updated_at": "2015-01-28T09:52:53Z",
  "translation_key": {
    "id": "abcd1234cdef1234abcd1234cdef1234",
    "name": "home.index.headline",
    "description": "My description for this key...",
    "name_hash": "1b31d2580ce324f246f66b3be00ed399",
    "plural": false,
    "tags": [
      "awesome-feature",
      "needs-proofreading"
    ],
    "data_type": "string",
    "created_at": "2015-01-28T09:52:53Z",
    "updated_at": "2015-01-28T09:52:53Z"
  }
}