getCurrent () {
    return new Promise((resolve, reject) => {
      Vue.axios.get('api/user')
        .then((response) => {
          store.commit('setUser', response.data);
          resolve(response.data);
        }, (error) => {
          reject(error);
        });
    });
  }
Gets current user from the server and caches it
@returns {Promise} Promise A promise object that signals the completion
                           or rejection of the request.