upgrade erlware_commons for OTP-19 fix

rebar.config

@@ -1,7 +1,7 @@
 %% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
 %% ex: ts=4 sw=4 ft=erlang et
 
-{deps, [{erlware_commons,     "0.20.0"},
+{deps, [{erlware_commons,     "0.21.0"},
         {ssl_verify_hostname, "1.0.5"},
         {certifi,             "0.4.0"},
         {providers,           "1.6.0"},

rebar.lock

@@ -2,7 +2,7 @@
  {<<"certifi">>,{pkg,<<"certifi">>,<<"0.4.0">>},0},
  {<<"cf">>,{pkg,<<"cf">>,<<"0.2.1">>},0},
  {<<"cth_readable">>,{pkg,<<"cth_readable">>,<<"1.2.2">>},0},
- {<<"erlware_commons">>,{pkg,<<"erlware_commons">>,<<"0.20.0">>},0},
+ {<<"erlware_commons">>,{pkg,<<"erlware_commons">>,<<"0.21.0">>},0},
  {<<"eunit_formatters">>,{pkg,<<"eunit_formatters">>,<<"0.3.1">>},0},
  {<<"getopt">>,{pkg,<<"getopt">>,<<"0.8.2">>},0},
  {<<"providers">>,{pkg,<<"providers">>,<<"1.6.0">>},0},