Add support for keypairs

Adds support for the following keypair operations:
- ListKeyPairs yields the list of available keypairs.
- CreateKeyPairs will create or generate a new keypair.
- DeleteKeyPair wil delete a keypair.
- ShowKeyPair will yield the named keypair.
diff --git a/keypairs.go b/keypairs.go
new file mode 100644
index 0000000..37bd456
--- /dev/null
+++ b/keypairs.go
@@ -0,0 +1,96 @@
+package gophercloud
+
+import (
+	"github.com/racker/perigee"
+)
+
+// See the CloudImagesProvider interface for details.
+func (gsp *genericServersProvider) ListKeyPairs() ([]KeyPair, error) {
+	type KeyPairs struct {
+		KeyPairs []struct {
+			KeyPair KeyPair `json:"keypair"`
+		} `json:"keypairs"`
+	}
+
+	var kp KeyPairs
+
+	err := gsp.context.WithReauth(gsp.access, func() error {
+		url := gsp.endpoint + "/os-keypairs"
+		return perigee.Get(url, perigee.Options{
+			CustomClient: gsp.context.httpClient,
+			Results:      &kp,
+			MoreHeaders: map[string]string{
+				"X-Auth-Token": gsp.access.AuthToken(),
+			},
+		})
+	})
+
+	// Flatten out the list of keypairs
+	var keypairs []KeyPair
+	for _, k := range kp.KeyPairs {
+		keypairs = append(keypairs, k.KeyPair)
+	}
+	return keypairs, err
+}
+
+func (gsp *genericServersProvider) CreateKeyPair(nkp NewKeyPair) (KeyPair, error) {
+	var kp KeyPair
+
+	err := gsp.context.WithReauth(gsp.access, func() error {
+		url := gsp.endpoint + "/os-keypairs"
+		return perigee.Post(url, perigee.Options{
+			ReqBody: &struct {
+				KeyPair *NewKeyPair `json:"keypair"`
+			}{&nkp},
+			CustomClient: gsp.context.httpClient,
+			Results:      &struct{ KeyPair *KeyPair }{&kp},
+			MoreHeaders: map[string]string{
+				"X-Auth-Token": gsp.access.AuthToken(),
+			},
+		})
+	})
+	return kp, err
+}
+
+// See the CloudImagesProvider interface for details.
+func (gsp *genericServersProvider) DeleteKeyPair(name string) error {
+	err := gsp.context.WithReauth(gsp.access, func() error {
+		url := gsp.endpoint + "/os-keypairs/" + name
+		return perigee.Delete(url, perigee.Options{
+			CustomClient: gsp.context.httpClient,
+			MoreHeaders: map[string]string{
+				"X-Auth-Token": gsp.access.AuthToken(),
+			},
+			OkCodes: []int{202},
+		})
+	})
+	return err
+}
+
+func (gsp *genericServersProvider) ShowKeyPair(name string) (KeyPair, error) {
+	var kp KeyPair
+
+	err := gsp.context.WithReauth(gsp.access, func() error {
+		url := gsp.endpoint + "/os-keypairs/" + name
+		return perigee.Get(url, perigee.Options{
+			CustomClient: gsp.context.httpClient,
+			Results:      &struct{ KeyPair *KeyPair }{&kp},
+			MoreHeaders: map[string]string{
+				"X-Auth-Token": gsp.access.AuthToken(),
+			},
+		})
+	})
+	return kp, err
+}
+
+type KeyPair struct {
+	FingerPrint string `json:"fingerprint"`
+	Name        string `json:"name"`
+	PublicKey   string `json:"public_key"`
+	UserID      string `json:"user_id,omitempty"`
+}
+
+type NewKeyPair struct {
+	Name      string `json:"name"`
+	PublicKey string `json:"public_key,omitempty"`
+}