Use full month name in release name.

Author: ningfei

appveyor.yml

@@ -20,6 +20,8 @@ init:
 
     Update-AppveyorBuild -Version "$($env:DATE)_g${githash}"
 
+    $env:release_version = $(Get-Date -Format d-MMMM-yyyy)
+
 before_build:
 - cmd: >-
     echo "Running cmake"
@@ -48,7 +50,7 @@ artifacts:
 deploy:
   - provider: GitHub
     tag: $(appveyor_repo_tag_name)
-    release: version $(date) ($(appveyor_repo_tag_name))
+    release: version $(release_version) ($(appveyor_repo_tag_name))
     description: ""
     auth_token:
       secure: k+sHhWGYpSAInN3H6TJltthRopDsvB1nIa1aPulvIMYM07t5nw9rJallMUND1tLP