Bump elvis DRY threshold because of hstore codec

rebar.config

@@ -27,6 +27,7 @@
      rules =>
          [{elvis_style, line_length, #{limit => 120}},
           {elvis_style, god_modules, #{limit => 41}},
+          {elvis_style, dont_repeat_yourself, #{min_complexity => 11}},
           {elvis_style, state_record_and_type, disable} % epgsql_sock
          ]}
   ]