Changelog for the 0.40.0 release

Signed-off-by: Fred Bricon <fbricon@gmail.com>

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Change Log
 
+## [0.40.0 (June 5th, 2019)](https://github.com/eclipse/eclipse.jdt.ls/milestone/58?closed=1)
+* enhancement - added code action to generate constructors. See [#972](https://github.com/eclipse/eclipse.jdt.ls/issues/972).
+* enhancement - added code action to generate delegate methods. See [#1042](https://github.com/eclipse/eclipse.jdt.ls/issues/1042).
+* enhancement - updated buildship to 3.1.0. See [Buildship changelog](https://discuss.gradle.org/t/buildship-3-1-is-now-available/31600).
+* enhancement - updated m2e to 1.12 (now embeds Maven 3.6.1). See [m2e changelog](https://projects.eclipse.org/projects/technology.m2e/releases/1.12/bugs).
+* enhancement - provide more info on hover for constant fields. See [#1049](https://github.com/eclipse/eclipse.jdt.ls/issues/1049).
+* bug fix - fixed Signature Help didn't match active parameter per type. See [#1037](https://github.com/eclipse/eclipse.jdt.ls/issues/1037).
+* bug fix - fixed disabling Gradle wrapper in certain cases. See [#1044](https://github.com/eclipse/eclipse.jdt.ls/issues/1044).
 
 ## [0.39.0 (May 15th, 2019)](https://github.com/eclipse/eclipse.jdt.ls/milestone/57?closed=1)
 * enhancement - added `Assign parameters to new fields` source actions. See [#167](https://github.com/eclipse/eclipse.jdt.ls/issues/167).