[BUGFIX] Pin doctrine/migrations to known working version
[BUGFIX] Pin doctrine/migrations to known working version

With doctrine/migrations not having had a stable branch for years,
Flow always required dev-master. Now that conflicts with the version
of doctrine/orm used with Flow 2.x, so we need to pin the required
version to the last known working state.

Change-Id: I3b412911d5d0c1441ec8413a570b4d7f2e15f6b6
Releases: 2.3, 2.2, 2.1
Fixes: FLOW-300
Original-Commit-Hash: 62f36644a50b9c85b1f5e03dc8a6c722e0564278

dlubitz/flow-development-collection,kdambekalns/flow-development-collection,aertmann/flow-development-collection,albe/flow-development-collection,kdambekalns/flow-development-collection,robertlemke/flow-development-collection,aertmann/flow-development-collection,daniellienert/flow-development-collection,gerhard-boden/flow-development-collection,mkeitsch/flow-development-collection,gerhard-boden/flow-development-collection,kdambekalns/flow-development-collection,gerhard-boden/flow-development-collection,dfeyer/flow-development-collection,bwaidelich/flow-development-collection,neos/flow-development-collection,albe/flow-development-collection,bwaidelich/flow-development-collection,kdambekalns/flow-development-collection,mkeitsch/flow-development-collection,kitsunet/flow-development-collection,fcool/flow-development-collection,daniellienert/flow-development-collection,dfeyer/flow-development-collection,robertlemke/flow-development-collection,kitsunet/flow-development-collection,robertlemke/flow-development-collection,neos/flow-development-collection,chewbakartik/flow-development-collection,dlubitz/flow-development-collection,fcool/flow-development-collection,albe/flow-development-collection,bwaidelich/flow-development-collection,fcool/flow-development-collection,robertlemke/flow-development-collection,chewbakartik/flow-development-collection,fcool/flow-development-collection,neos/flow-development-collection,daniellienert/flow-development-collection,dfeyer/flow-development-collection,dlubitz/flow-development-collection,mkeitsch/flow-development-collection,dfeyer/flow-development-collection,aertmann/flow-development-collection,neos/flow-development-collection,kitsunet/flow-development-collection,chewbakartik/flow-development-collection