adds server to serve the static files, fixes db tables

lootalot_db/migrations/2019-06-10-123940_create_players/up.sql

@@ -1,9 +1,9 @@
 CREATE TABLE players (
-  id INTEGER PRIMARY KEY,
+  id INTEGER PRIMARY KEY NOT NULL,
   name VARCHAR NOT NULL,
-  debt INTEGER DEFAULT 0, -- debt to the group in copper pieces
-  cp INTEGER DEFAULT 0,
-  sp INTEGER DEFAULT 0,
-  gp INTEGER DEFAULT 0,
-  pp INTEGER DEFAULT 0
+  debt INTEGER DEFAULT 0 NOT NULL, -- debt to the group in copper pieces
+  cp INTEGER DEFAULT 0 NOT NULL,
+  sp INTEGER DEFAULT 0 NOT NULL,
+  gp INTEGER DEFAULT 0 NOT NULL,
+  pp INTEGER DEFAULT 0 NOT NULL
 );