Feature/filestorage securityservices create (#132)

* sfs: Add support for security services Create

* sfs: Add acceptance tests for security service Create

* sfs: Fix comments
diff --git a/openstack/sharedfilesystems/v2/securityservices/requests.go b/openstack/sharedfilesystems/v2/securityservices/requests.go
new file mode 100644
index 0000000..eca9fe5
--- /dev/null
+++ b/openstack/sharedfilesystems/v2/securityservices/requests.go
@@ -0,0 +1,61 @@
+package securityservices
+
+import "github.com/gophercloud/gophercloud"
+
+type SecurityServiceType string
+
+// Valid security service types
+const (
+	LDAP            SecurityServiceType = "ldap"
+	Kerberos        SecurityServiceType = "kerberos"
+	ActiveDirectory SecurityServiceType = "active_directory"
+)
+
+// CreateOptsBuilder allows extensions to add additional parameters to the
+// Create request.
+type CreateOptsBuilder interface {
+	ToSecurityServiceCreateMap() (map[string]interface{}, error)
+}
+
+// CreateOpts contains options for creating a SecurityService. This object is
+// passed to the securityservices.Create function. For more information about
+// these parameters, see the SecurityService object.
+type CreateOpts struct {
+	// The security service type. A valid value is ldap, kerberos, or active_directory
+	Type SecurityServiceType `json:"type" required:"true"`
+	// The security service name
+	Name string `json:"name,omitempty"`
+	// The security service description
+	Description string `json:"description,omitempty"`
+	// The DNS IP address that is used inside the tenant network
+	DNSIP string `json:"dns_ip,omitempty"`
+	// The security service user or group name that is used by the tenant
+	User string `json:"user,omitempty"`
+	// The user password, if you specify a user
+	Password string `json:"password,omitempty"`
+	// The security service domain
+	Domain string `json:"domain,omitempty"`
+	// The security service host name or IP address
+	Server string `json:"server,omitempty"`
+}
+
+// ToSecurityServicesCreateMap assembles a request body based on the contents of a
+// CreateOpts.
+func (opts CreateOpts) ToSecurityServiceCreateMap() (map[string]interface{}, error) {
+	return gophercloud.BuildRequestBody(opts, "security_service")
+}
+
+// Create will create a new SecurityService based on the values in CreateOpts. To
+// extract the SecurityService object from the response, call the Extract method
+// on the CreateResult.
+func Create(client *gophercloud.ServiceClient, opts CreateOptsBuilder) (r CreateResult) {
+	b, err := opts.ToSecurityServiceCreateMap()
+	if err != nil {
+		r.Err = err
+		return
+	}
+	_, r.Err = client.Post(createURL(client), b, &r.Body, &gophercloud.RequestOpts{
+		OkCodes: []int{200},
+	})
+	return
+}