Update for optimize command.
Setup composer post update script to run php artisan optimize.
Merge remote-tracking branch 'upstream/develop' into develop

# By Taylor Otwell
# Via Taylor Otwell
* upstream/develop:
  Setup composer post update script to run php artisan optimize.
  Update for optimize command.
Fix comment.
Added new workbench config file.
Typo: missing quotes in session.php doc block
Merge pull request #1800 from AndreiCanta/develop

Typo: missing quotes in session.php doc block
Fix validation language line.
Added a default robots.txt file.
Remove fallback locale.
Merge remote-tracking branch 'upstream/develop' into develop

# By Taylor Otwell (5) and AndreiCanta (1)
# Via Taylor Otwell
* upstream/develop:
  Remove fallback locale.
  Added a default robots.txt file.
  Fix validation language line.
  Typo: missing quotes in session.php doc block
  Added new workbench config file.
  Fix comment.
Updating framework & composer updates