diff -r e77dad242f4c -r 2a9ec03fe5a1 vendor/github.com/sendgrid/rest/rest.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/github.com/sendgrid/rest/rest.go	Sat Sep 29 18:09:54 2018 +0200
@@ -0,0 +1,157 @@
+// Package rest allows for quick and easy access any REST or REST-like API.
+package rest
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+)
+
+// Method contains the supported HTTP verbs.
+type Method string
+
+// Supported HTTP verbs.
+const (
+	Get    Method = "GET"
+	Post   Method = "POST"
+	Put    Method = "PUT"
+	Patch  Method = "PATCH"
+	Delete Method = "DELETE"
+)
+
+// Request holds the request to an API Call.
+type Request struct {
+	Method      Method
+	BaseURL     string // e.g. https://api.sendgrid.com
+	Headers     map[string]string
+	QueryParams map[string]string
+	Body        []byte
+}
+
+// RestError is a struct for an error handling.
+type RestError struct {
+	Response *Response
+}
+
+// Error is the implementation of the error interface.
+func (e *RestError) Error() string {
+	return e.Response.Body
+}
+
+// DefaultClient is used if no custom HTTP client is defined
+var DefaultClient = &Client{HTTPClient: http.DefaultClient}
+
+// Client allows modification of client headers, redirect policy
+// and other settings
+// See https://golang.org/pkg/net/http
+type Client struct {
+	HTTPClient *http.Client
+}
+
+// Response holds the response from an API call.
+type Response struct {
+	StatusCode int                 // e.g. 200
+	Body       string              // e.g. {"result: success"}
+	Headers    map[string][]string // e.g. map[X-Ratelimit-Limit:[600]]
+}
+
+// AddQueryParameters adds query parameters to the URL.
+func AddQueryParameters(baseURL string, queryParams map[string]string) string {
+	baseURL += "?"
+	params := url.Values{}
+	for key, value := range queryParams {
+		params.Add(key, value)
+	}
+	return baseURL + params.Encode()
+}
+
+// BuildRequestObject creates the HTTP request object.
+func BuildRequestObject(request Request) (*http.Request, error) {
+	// Add any query parameters to the URL.
+	if len(request.QueryParams) != 0 {
+		request.BaseURL = AddQueryParameters(request.BaseURL, request.QueryParams)
+	}
+	req, err := http.NewRequest(string(request.Method), request.BaseURL, bytes.NewBuffer(request.Body))
+	if err != nil {
+		return req, err
+	}
+	for key, value := range request.Headers {
+		req.Header.Set(key, value)
+	}
+	_, exists := req.Header["Content-Type"]
+	if len(request.Body) > 0 && !exists {
+		req.Header.Set("Content-Type", "application/json")
+	}
+	return req, err
+}
+
+// MakeRequest makes the API call.
+func MakeRequest(req *http.Request) (*http.Response, error) {
+	return DefaultClient.HTTPClient.Do(req)
+}
+
+// BuildResponse builds the response struct.
+func BuildResponse(res *http.Response) (*Response, error) {
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err := res.Body.Close(); err != nil {
+			return // maybe log in the future
+		}
+	}()
+	response := Response{
+		StatusCode: res.StatusCode,
+		Body:       string(body),
+		Headers:    res.Header,
+	}
+	return &response, nil
+}
+
+// API supports old implementation (deprecated)
+func API(request Request) (*Response, error) {
+	return Send(request)
+}
+
+// Send uses the DefaultClient to send your request
+func Send(request Request) (*Response, error) {
+	return DefaultClient.Send(request)
+}
+
+// The following functions enable the ability to define a
+// custom HTTP Client
+
+// MakeRequest makes the API call.
+func (c *Client) MakeRequest(req *http.Request) (*http.Response, error) {
+	return c.HTTPClient.Do(req)
+}
+
+// API supports old implementation (deprecated)
+func (c *Client) API(request Request) (*Response, error) {
+	return c.Send(request)
+}
+
+// Send will build your request, make the request, and build your response.
+func (c *Client) Send(request Request) (*Response, error) {
+	// Build the HTTP request object.
+	req, err := BuildRequestObject(request)
+	if err != nil {
+		return nil, err
+	}
+
+	// Build the HTTP client and make the request.
+	res, err := c.MakeRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// Build Response object.
+	response, err := BuildResponse(res)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}