message: remove redundant store() calls from readme
diff: @@ -32,7 +32,6 @@ session
  .load('users/1-A')
  .then((user) => {
  user.password = PBKDF2('new password');
  - return session.store(user);
  })
  .then(() => session.saveChanges())
  .then(() => {
  @@ -47,7 +46,6 @@ session
  const session = store.openSession();
  let user = await store.load('users/1-A');
  user.password = PBKDF2('new password');
  -await session.store(user);
  await session.saveChanges();
  ```
  2. Promises
  @@ -55,7 +53,6 @@ await session.saveChanges();
  session.load('Users/1-A')
  .then((user) => {
  user.password = PBKDF2('new password');
  - return session.store(user);
  })
  .then(() => session.saveChanges())
  .then(() => {
  @@ -66,12 +63,10 @@ session.load('Users/1-A')
  ```javascript
  session.load('users/1-A', (user) => {
  user.password = PBKDF2('new password');
  - session.store(user, () => {
  session.saveChanges(() => {
  // data is persisted
  });
  });
  -});
  ```
  ## CRUD example
  @@ -104,7 +99,6 @@ console.log(product.id); // Products/1-A
  let product = await session.load('products/1-A');
  product.in_stock = false;
  product.last_update = new Date();
  -await session.store(product);
  await session.saveChanges();
  // ...
  product = await session.load('products/1-A');
  