Doctrine inflector 2 revisit

[mmarton]

Since the today released doctrine orm 2.8, maker-bundle is the last pacakage that stuck on doctrine inflector 1. (in my proejects)

$ composer why-not doctrine/inflector:2
symfony/maker-bundle v1.24.2 requires doctrine/inflector (^1.2)

As said in this PR: #611

Dropping support for v2 isn't really a fix, but will make it more
compatible with the ecosystem at the current time. Later, especially
when doctrine/orm allows 2, we can again.

[jrushlow]

thanks @mmarton for the heads up! I've created a PR to reintroduce support, I don't see a problem with this as long as our tests pass. stay tuned!