API & Client: add an activity w/o gpx

mpwo_client/src/mwpoApi/activities.js

@@ -15,6 +15,20 @@ export default class MpwoApi {
       .catch(error => error)
   }
 
+  static addActivityWithoutGpx(data) {
+    const request = new Request(`${apiUrl}activities/no_gpx`, {
+      method: 'POST',
+      headers: new Headers({
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${window.localStorage.getItem('authToken')}`,
+      }),
+      body: JSON.stringify(data)
+    })
+    return fetch(request)
+      .then(response => response.json())
+      .catch(error => error)
+  }
+
   static getActivityGpx(activityId) {
     const request = new Request(`${apiUrl}activities/${activityId}/gpx`, {
       method: 'GET',