To update the details of a task:
PUT api/enterprise/tasks/{taskId}
    with a json body that can contain name, description and dueDate (ISO 8601 string)
For example:
Example request:
{
  "name" : "IchangedTaskName",
  "description" : "description-updated",
  "dueDate" : "2015-01-11T22:59:59.000Z",
  "priority":10,
  "formKey": "100"
}
To delegate a task:
PUT api/enterprise/tasks/{taskId}/action/delegate
    Example request:
{
     "userId": "1000"
}
    To resolve a task:
PUT api/enterprise/tasks/{taskId}/action/resolve
    To complete a task (standalone or without a task form) (Note: No json body needed!):
PUT api/enterprise/tasks/{taskId}/action/complete
    To claim a task (in case the task is assigned to a group):
PUT api/enterprise/tasks/{taskId}/action/claim
    No json body needed. The task will be claimed by the user in the authentication credentials.
To assign a task to a user:
PUT api/enterprise/tasks/{taskId}/action/assign
with a json body that contains the assignee property set to the ID of a user.
To involve a user with a task:
PUT api/enterprise/tasks/{taskId}/action/involve
    with a json body that contains the userId property set to the ID of a user.
To remove an involved user from a task:
PUT api/enterprise/tasks/{taskId}/action/remove-involved
    with a json body that contains the userId property set to the ID of a user.
To attach a form to a task:
PUT api/enterprise/tasks/{taskId}/action/attach-form
    with a json body that contains the formId property set to the the ID of a form.
To attach a form to a task:
DELETE api/enterprise/tasks/{taskId}/action/remove-form