Fix: ExecuteCommand

[rcatlin]

• Fix \Doctrine\DBAL\Migrations\Tools\Console\Command\ExecuteCommand unable to find Migration Version by registering Migration Versions on call to \Doctrine\DBAL\Migrations\Configuration\Configuration#getVersion()
• Adds missing check for empty migrations array in \Doctrine\DBAL\Migrations\Configuration\Configuration#getVersion()
• Commit 916bee2 previously added checks for registered migrations (Pull Request Fix issue with some method when the migrations were not loaded #421)
• Added tests for \Doctrine\DBAL\Migrations\Configuration\Configuration#getVersion()

Fix issue with some method call order when the migrations were not loaded

Previously you needed to make sure manually that registerMigrations was
called before to make any call to a method that was using the migrations
loaded.

This might cause performance issue in some edge case but it's unlikely.
Unfortunately in the current desgin I don't see any other solution.

[rcatlin]

@mikeSimonson review?

[mikeSimonson]

@rcatlin Can you add a test for it ?

[rcatlin]

@mikeSimonson Absolutely!

[rcatlin]

@mikeSimonson Added tests for Configuration#getVersion(). Please take another look when you have a chance.

[mikeSimonson]

@rcatlin Thanks

[stof]

Putting this after the call to getSqliteConfiguration would be even better, as it would enforce the exception to happen in getVersion rather than getSqliteConfiguration (which is the drawback of the @expectedException annotation btw)

[rcatlin]

That's an excellent point! I'll put up a PR with the change.

[rcatlin]

Note: Pull Request created #435