add nonbinary option to gender step of join flow

src/components/join-flow/gender-step.jsx

@@ -98,6 +98,12 @@ class GenderStep extends React.Component {
                                 value="Male"
                                 onSetFieldValue={setFieldValue}
                             />
+                            <GenderOption
+                                label={this.props.intl.formatMessage({id: 'general.nonbinary'})}
+                                selectedValue={values.gender}
+                                value="Non-binary"
+                                onSetFieldValue={setFieldValue}
+                            />
                             <div
                                 className={classNames(
                                     'col-sm-9',

src/l10n.json

@@ -61,6 +61,7 @@
     "general.noDeletionTitle": "Your Account Will Not Be Deleted",
     "general.noDeletionDescription": "Your account was scheduled for deletion but you logged in. Your account has been reactivated. If you didn’t request for your account to be deleted, you should {resetLink} to make sure your account is secure.",
     "general.noDeletionLink": "change your password",
+    "general.nonBinary": "Non-binary",
     "general.notRequired": "Not Required",
     "general.okay": "Okay",
     "general.other": "Other",