Simplified DB check.

lib/health_monitor/providers/database.rb

@@ -5,8 +5,7 @@ class DatabaseException < StandardError; end
     class Database
       def check!
         # Check connection to the DB:
-        query = 'SELECT version FROM schema_migrations'
-        ActiveRecord::Base.connection.select_value(query).to_i
+        ActiveRecord::Migrator.current_version
       rescue Exception => e
         raise DatabaseException.new(e.message)
       end

spec/support/providers.rb

@@ -6,7 +6,7 @@ def stub_cache_failure
   end
 
   def stub_database_failure
-    ActiveRecord::Base.connection.stub(:select_value).and_raise(Exception)
+    ActiveRecord::Migrator.stub(:current_version).and_raise(Exception)
   end
 
   def stub_redis_failure