Unlock pg verson

Get a warning about `async_exec`, but it seems that build has passed
through the fix of https://bitbucket.org/ged/ruby-pg/commits/be48d118eeedbf6b6a1f0aa14749ab97fc22065c.

1 files changed, 1 insertions, 1 deletions

diff --git a/Gemfile b/Gemfile
index 1b0224dfdf..5bf443b7c8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -121,7 +121,7 @@ platforms :ruby, :mswin, :mswin64, :mingw, :x64_mingw do
   gem "sqlite3", "~> 1.3.6"
 
   group :db do
-    gem "pg", ">= 0.18.0", "< 1.1"
+    gem "pg", ">= 0.18.0"
     gem "mysql2", ">= 0.4.10"
   end
 end