Rails 5.1 - Replace sanitize (no longer public method) (#359)

* remove version constraints and update next? dual boot to run rails 5.1

* remove version constraint for dev dependency spring

* replace sanitize with .connection.quote

app/models/concerns/hstore_update.rb

@@ -18,7 +18,7 @@ def hstore_update(column, updater)
   end
 
   def hstore_sanitize(string)
-    self.class.sanitize string.to_s.gsub /["'=>\(\)]/, ''
+    self.class.connection.quote string.to_s.gsub /["'=>\(\)]/, ''
   end
 
   def hstore_escape(key_pairs)