Rename authorize to authorize-session (#531)

As pointed out by Rob, this makes it clearer what the action actually
is. We were sort of torn on it before, but I've definitely come around
to it.

api/targets/custom.go

@@ -25,9 +25,9 @@ func (n SessionAuthorizationResult) GetResponseMap() map[string]interface{} {
 	return n.responseMap
 }
 
-func (c *Client) Authorize(ctx context.Context, targetId string, opt ...Option) (*SessionAuthorizationResult, error) {
+func (c *Client) AuthorizeSession(ctx context.Context, targetId string, opt ...Option) (*SessionAuthorizationResult, error) {
 	if targetId == "" {
-		return nil, fmt.Errorf("empty targetId value passed into Authorize request")
+		return nil, fmt.Errorf("empty targetId value passed into AuthorizeSession request")
 	}
 
 	opts, apiOpts := getOpts(opt...)
@@ -36,9 +36,9 @@ func (c *Client) Authorize(ctx context.Context, targetId string, opt ...Option)
 		return nil, fmt.Errorf("nil client")
 	}
 
-	req, err := c.client.NewRequest(ctx, "POST", fmt.Sprintf("targets/%s:authorize", targetId), opts.postMap, apiOpts...)
+	req, err := c.client.NewRequest(ctx, "POST", fmt.Sprintf("targets/%s:authorize-session", targetId), opts.postMap, apiOpts...)
 	if err != nil {
-		return nil, fmt.Errorf("error creating Authorize request: %w", err)
+		return nil, fmt.Errorf("error creating AuthorizeSession request: %w", err)
 	}
 
 	if len(opts.queryMap) > 0 {
@@ -51,14 +51,14 @@ func (c *Client) Authorize(ctx context.Context, targetId string, opt ...Option)
 
 	resp, err := c.client.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("error performing client request during Authorize call: %w", err)
+		return nil, fmt.Errorf("error performing client request during AuthorizeSession call: %w", err)
 	}
 
 	sar := new(SessionAuthorizationResult)
 	sar.Item = new(SessionAuthorization)
 	apiErr, err := resp.Decode(sar.Item)
 	if err != nil {
-		return nil, fmt.Errorf("error decoding Authorize response: %w", err)
+		return nil, fmt.Errorf("error decoding AuthorizeSession response: %w", err)
 	}
 	if apiErr != nil {
 		return nil, apiErr