Add changelog for 1.1.7

Author: alcaeus

CHANGELOG-1.1.md

@@ -5,6 +5,18 @@ This changelog references the relevant changes done in 1.1 minor versions. If up
 1.0.x branch, please review
 [Upgrade Path](https://github.com/doctrine/mongodb-odm/blob/master/CHANGELOG-1.1.md#upgrade-path).
 
+1.1.7 (2017-10-23)
+------------------
+
+All issues and pull requests in this release may be found under the
+[1.1.7 milestone](https://github.com/doctrine/mongodb-odm/issues?q=milestone%3A1.1.7).
+
+* [#1642](https://github.com/doctrine/mongodb-odm/pull/1642) fixes the return type of `DocumentManager::getHydratorFactory`.
+* [#1636](https://github.com/doctrine/mongodb-odm/pull/1636) fixes reference preparation when using `storeAs=dbRef` with no `targetDocument`.
+* [#1646](https://github.com/doctrine/mongodb-odm/pull/1646) fixes invalid UUID data in tests with new driver versions.
+* [#1649](https://github.com/doctrine/mongodb-odm/pull/1649) fixes the version constraint for `doctrine/instantiator`, allowing newer versions to be installed.
+
+
 1.1.6 (2017-08-19)
 ------------------