Constructor
new PowerSchoolAPI(url, apiUsernameopt, apiPasswordopt)
    Create an API wrapper.
    Parameters:
| Name | Type | Attributes | Default | Description | 
|---|---|---|---|---|
url | 
            
            string | The main URL of the PowerSchool installation, such as "http://sales.powerschool.com". | ||
apiUsername | 
            
            string | 
                
                    <optional> | 
            
            
                pearson | The API username to use for logging in, if your installation has a different one. For most installations, the default provided value should work. | 
apiPassword | 
            
            string | 
                
                    <optional> | 
            
            
                m0bApP5 | The API password to use for logging in, if your installation has a different one. For most installations, the default provided value should work. | 
Methods
login(username, password) → {Promise.<PowerSchoolUser, Error>}
    Log into a user's account and get their user object.
    Parameters:
| Name | Type | Description | 
|---|---|---|
username | 
            
            string | The username of the account to log in to. | 
password | 
            
            string | The password of the account to log in to. | 
Returns:
    - A promise that resolves with the user if login was successful, resolves to null if invalid credentials were provided, and rejects with an Error if another error occurred during login.
- Type
 - Promise.<PowerSchoolUser, Error>
 
setup() → {Promise.<PowerSchoolAPI, Error>}
    Setup the API wrapper for usage (required for any interaction).
Returns:
    - A promise that returns the API again if resolved, or an Error if rejected.
- Type
 - Promise.<PowerSchoolAPI, Error>