2.11.0 readiness

- Set release date for 2.11.0 in CHANGELOG
- Updated branch aliases:
  - dev-master => 2.11.x-dev
  - dev-develop => 2.12.x-dev

Signed-off-by: Matthew Weier O'Phinney <matthew@weierophinney.net>

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 2.11.0 - TBD
+## 2.11.0 - 2020-06-30
 
 ### Added
 

composer.json

@@ -20,8 +20,8 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.10.x-dev",
-            "dev-develop": "2.11.x-dev"
+            "dev-master": "2.11.x-dev",
+            "dev-develop": "2.12.x-dev"
         },
         "laminas": {
             "component": "Laminas\\Mail",