Digitalocean provider (#171)

* Implement Digitalocean provider
* Vendor digitalocean lib
* Enable SRV for Digitalocean and fix the tests
* Test cname etc. records pointing to the same domain

vendor/github.com/digitalocean/godo/links.go

@@ -0,0 +1,84 @@
+package godo
+
+import (
+	"net/url"
+	"strconv"
+
+	"github.com/digitalocean/godo/context"
+)
+
+// Links manages links that are returned along with a List
+type Links struct {
+	Pages   *Pages       `json:"pages,omitempty"`
+	Actions []LinkAction `json:"actions,omitempty"`
+}
+
+// Pages are pages specified in Links
+type Pages struct {
+	First string `json:"first,omitempty"`
+	Prev  string `json:"prev,omitempty"`
+	Last  string `json:"last,omitempty"`
+	Next  string `json:"next,omitempty"`
+}
+
+// LinkAction is a pointer to an action
+type LinkAction struct {
+	ID   int    `json:"id,omitempty"`
+	Rel  string `json:"rel,omitempty"`
+	HREF string `json:"href,omitempty"`
+}
+
+// CurrentPage is current page of the list
+func (l *Links) CurrentPage() (int, error) {
+	return l.Pages.current()
+}
+
+func (p *Pages) current() (int, error) {
+	switch {
+	case p == nil:
+		return 1, nil
+	case p.Prev == "" && p.Next != "":
+		return 1, nil
+	case p.Prev != "":
+		prevPage, err := pageForURL(p.Prev)
+		if err != nil {
+			return 0, err
+		}
+
+		return prevPage + 1, nil
+	}
+
+	return 0, nil
+}
+
+// IsLastPage returns true if the current page is the last
+func (l *Links) IsLastPage() bool {
+	if l.Pages == nil {
+		return true
+	}
+	return l.Pages.isLast()
+}
+
+func (p *Pages) isLast() bool {
+	return p.Last == ""
+}
+
+func pageForURL(urlText string) (int, error) {
+	u, err := url.ParseRequestURI(urlText)
+	if err != nil {
+		return 0, err
+	}
+
+	pageStr := u.Query().Get("page")
+	page, err := strconv.Atoi(pageStr)
+	if err != nil {
+		return 0, err
+	}
+
+	return page, nil
+}
+
+// Get a link action by id.
+func (la *LinkAction) Get(ctx context.Context, client *Client) (*Action, *Response, error) {
+	return client.Actions.Get(ctx, la.ID)
+}