Updated outdated dependencies

Author: bigardone

mix.lock

@@ -2,7 +2,7 @@
   "earmark": {:hex, :earmark, "0.2.1"},
   "ex_doc": {:hex, :ex_doc, "0.11.4"},
   "exactor": {:hex, :exactor, "2.2.0"},
-  "excoveralls": {:hex, :excoveralls, "0.4.5"},
+  "excoveralls": {:hex, :excoveralls, "0.5.1"},
   "exjsx": {:hex, :exjsx, "3.2.0"},
   "exvcr": {:hex, :exvcr, "0.7.1"},
   "hackney": {:hex, :hackney, "1.4.8"},
@@ -12,5 +12,5 @@
   "jsx": {:hex, :jsx, "2.6.2"},
   "meck": {:hex, :meck, "0.8.4"},
   "mimerl": {:hex, :mimerl, "1.0.2"},
-  "poison": {:hex, :poison, "2.0.1"},
+  "poison": {:hex, :poison, "2.1.0"},
   "ssl_verify_hostname": {:hex, :ssl_verify_hostname, "1.0.5"}}