Using integers in `connect_timeout`

Fixes the error `PG::ConnectionBad: invalid integer value "2.5" for
connection option "connect_timeout"`

config/database.yml.sample

@@ -8,7 +8,7 @@ production:
   username: postgres
   password:
   conn_validator_timeout: 900
-  connect_timeout: 2.5
+  connect_timeout: 3
   prepared_statements: false
 
 staging:
@@ -21,7 +21,7 @@ staging:
   username: postgres
   password:
   conn_validator_timeout: 900
-  connect_timeout: 2.5
+  connect_timeout: 3
   prepared_statements: false
 
 development:
@@ -34,7 +34,7 @@ development:
   username: postgres
   password:
   conn_validator_timeout: 900
-  connect_timeout: 2.5
+  connect_timeout: 3
   pool: 50
   prepared_statements: false