Support limit for following (#38)

* Support limit for following

* Add tests for limit

controllers/me_following_users_controller.go

@@ -1,6 +1,8 @@
 package controllers
 
 import (
+	"strconv"
+
 	"github.com/BrandonRomano/wrecker"
 	"github.com/carrot/go-pinterest/models"
 )
@@ -22,6 +24,7 @@ func newMeFollowingUsersController(wc *wrecker.Wrecker) *MeFollowingUsersControl
 // parameters for the Fetch method
 type FollowingUsersControllerFetchOptionals struct {
 	Cursor string
+	Limit  int
 }
 
 // Fetch loads the users that the authorized user follows
@@ -36,6 +39,9 @@ func (c *MeFollowingUsersController) Fetch(optionals *FollowingUsersControllerFe
 	if optionals.Cursor != "" {
 		request.URLParam("cursor", optionals.Cursor)
 	}
+	if optionals.Limit != 0 {
+		request.URLParam("limit", strconv.Itoa(optionals.Limit))
+	}
 	httpResp, err := request.Execute()
 
 	// Check Error

pinterest_test.go

@@ -1083,13 +1083,14 @@ func (suite *ClientTestSuite) TestSuccessfulMeFollowingUsersFetch() {
 	assert.Equal(suite.T(), len(*users), 25)
 
 	// Load second page
-	suite.client.Me.Following.Users.Fetch(
+	users, _, err = suite.client.Me.Following.Users.Fetch(
 		&controllers.FollowingUsersControllerFetchOptionals{
 			Cursor: page.Cursor,
+			Limit:  3,
 		},
 	)
 	assert.Equal(suite.T(), nil, err)
-	assert.True(suite.T(), len(*users) > 0)
+	assert.True(suite.T(), len(*users) == 3)
 }
 
 // TestTimeoutMeFollowingUsersFetch tests that an error is appropriately thrown