POST [api-root-url]/sessions

authenticate

{
  "user": {
    "id": "52cace83374c10105e000005",
    "email": "jason@apprennet.com",
    "first_name": "Jason",
    "last_name": "Blanchard",
    "authentication_token": "HTjy9Qpm9XVvtjUJRTkH",
    "organizations": [
      {
        "id": "52cc5b74374c10355b000001",
        "name": "Jason Blanchard"
      },
      {
        "id": "5307a1dd374c100c64000001",
        "name": "Mike's Chris"
      },
      {
        "id": "530f9417374c1010af000003",
        "name": "LTI Testing Organization"
      },
      {
        "id": "531f2f65374c100e5900001f",
        "name": "Jeff's Chris"
      }
    ]
  }
}