Add comment field to Deploy Key response data structure (#169)

When you add a deploy key that contains a comment, the Bitbucket API splits out the comment and returns it in a separate `comment` field in the API.

For example,
`key = "ssh-rsa AAAA...=== [email protected]"`

API response
```
key = "ssh-rsa AAAA...==="
comment = "[email protected]"
```

deploykeys.go

@@ -13,9 +13,10 @@ type DeployKeys struct {
 }
 
 type DeployKey struct {
-	Id    int    `json:"id"`
-	Label string `json:"label"`
-	Key   string `json:"key"`
+	Id      int    `json:"id"`
+	Label   string `json:"label"`
+	Key     string `json:"key"`
+	Comment string `json:"comment"`
 }
 
 func decodeDeployKey(response interface{}) (*DeployKey, error) {

tests/deploykeys_test.go

@@ -1,6 +1,7 @@
 package tests
 
 import (
+	"fmt"
 	"os"
 	"testing"
 
@@ -100,3 +101,102 @@ func TestDeployKey(t *testing.T) {
 		}
 	})
 }
+
+func TestDeployKeyWithComment(t *testing.T) {
+	user := os.Getenv("BITBUCKET_TEST_USERNAME")
+	pass := os.Getenv("BITBUCKET_TEST_PASSWORD")
+	owner := os.Getenv("BITBUCKET_TEST_OWNER")
+	repo := os.Getenv("BITBUCKET_TEST_REPOSLUG")
+
+	if user == "" {
+		t.Error("BITBUCKET_TEST_USERNAME is empty.")
+	}
+	if pass == "" {
+		t.Error("BITBUCKET_TEST_PASSWORD is empty.")
+	}
+	if owner == "" {
+		t.Error("BITBUCKET_TEST_OWNER is empty.")
+	}
+	if repo == "" {
+		t.Error("BITBUCKET_TEST_REPOSLUG is empty.")
+	}
+
+	c := bitbucket.NewBasicAuth(user, pass)
+
+	var deployKeyResourceId int
+
+	label := "go-bb-test"
+	key := "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDAK/b1cHHDr/TEV1JGQl+WjCwStKG6Bhrv0rFpEsYlyTBm1fzN0VOJJYn4ZOPCPJwqse6fGbXntEs+BbXiptR+++HycVgl65TMR0b5ul5AgwrVdZdT7qjCOCgaSV74/9xlHDK8oqgGnfA7ZoBBU+qpVyaloSjBdJfLtPY/xqj4yHnXKYzrtn/uFc4Kp9Tb7PUg9Io3qohSTGJGVHnsVblq/rToJG7L5xIo0OxK0SJSQ5vuId93ZuFZrCNMXj8JDHZeSEtjJzpRCBEXHxpOPhAcbm4MzULgkFHhAVgp4JbkrT99/wpvZ7r9AdkTg7HGqL3rlaDrEcWfL7Lu6TnhBdq5"
+	comment := "[email protected]"
+
+	t.Run("create", func(t *testing.T) {
+		opt := &bitbucket.DeployKeyOptions{
+			Owner:    owner,
+			RepoSlug: repo,
+			Label:    label,
+			Key:      fmt.Sprintf("%s %s", key, comment),
+		}
+
+		deployKey, err := c.Repositories.DeployKeys.Create(opt)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if deployKey == nil {
+			t.Error("The Deploy Key could not be created.")
+		}
+
+		if deployKey.Label != label {
+			t.Error("The Deploy Key `label` attribute does not match the expected value.")
+		}
+		if deployKey.Key != key {
+			t.Error("The Deploy Key `key` attribute does not match the expected value.")
+		}
+		if deployKey.Comment != comment {
+			t.Error("The Deploy Key `comment` attribute does not match the expected value.")
+		}
+
+		deployKeyResourceId = deployKey.Id
+	})
+
+	t.Run("get", func(t *testing.T) {
+		opt := &bitbucket.DeployKeyOptions{
+			Owner:    owner,
+			RepoSlug: repo,
+			Id:       deployKeyResourceId,
+		}
+		deployKey, err := c.Repositories.DeployKeys.Get(opt)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if deployKey == nil {
+			t.Error("The Deploy Key could not be retrieved.")
+		}
+
+		if deployKey.Id != deployKeyResourceId {
+			t.Error("The Deploy Key `label` attribute does not match the expected value.")
+		}
+		if deployKey.Label != label {
+			t.Error("The Deploy Key `label` attribute does not match the expected value.")
+		}
+		if deployKey.Key != key {
+			t.Error("The Deploy Key `key` attribute does not match the expected value.")
+		}
+		if deployKey.Comment != comment {
+			t.Error("The Deploy Key `comment` attribute does not match the expected value.")
+		}
+	})
+
+	t.Run("delete", func(t *testing.T) {
+		opt := &bitbucket.DeployKeyOptions{
+			Owner:    owner,
+			RepoSlug: repo,
+			Id:       deployKeyResourceId,
+		}
+		_, err := c.Repositories.DeployKeys.Delete(opt)
+		if err != nil {
+			t.Error(err)
+		}
+	})
+}