Remove Doctrine

See: https://github.com/sindresorhus/awesome/issues/927#issuecomment-290915355

readme.md

@@ -346,7 +346,6 @@
 - [SQLAlchemy](https://github.com/dahlia/awesome-sqlalchemy)
 - [InfluxDB](https://github.com/mark-rushakoff/awesome-influxdb)
 - [Neo4j](https://github.com/Neueda4j/awesome-neo4j)
-- [Doctrine](https://github.com/TomasVotruba/awesome-doctrine) - PHP ORM.
 - [MongoDB](https://github.com/ramnes/awesome-mongodb) - NoSQL database.
 - [RethinkDB](https://github.com/d3viant0ne/awesome-rethinkdb)
 - [TinkerPop](https://github.com/mohataher/awesome-tinkerpop) - Graph computing framework.