Add created field to API Tokens.

api/src/main/sql/migrations/20190214122514-initial-schema-up.sql

@@ -14,6 +14,7 @@ create table "api_tokens" (
   id uuid default uuid_generate_v4() primary key,
   user_id uuid not null references users (id) on delete cascade on update cascade,
   name varchar not null,
+  created timestamp with time zone not null default current_timestamp,
   expires timestamp with time zone default null,
   hashed_token varchar not null
 );