Acquires an access token on behalf of a user.
| Header | Data Type | Valid Values | Required | Description | 
|---|---|---|---|---|
| Content-Type | string | application/json | YES | The format your data will be sent to our site. | 
| X-DevKey | string | string | YES | The devkey assigned to the developer. | 
NOTE: Variables to place in the body of the request.
| Parameter | Data Type | Valid Values | Description | 
|---|---|---|---|
| Username | string | string | The user's username. | 
| Password | string | string | The user's password. | 
    If the username or password are not valid, you will receive a 401 Unauthorized and a Message Response indicating the reason.
    If there are no errors with the input parameters, this call will respond with a 200 OK and the following data as serialized JSON
| Parameter | Data Type | Valid Values | Description | 
|---|---|---|---|
| AccessToken | string | string | The access token to use in the X-AccessToken header of subsequent requests. |