Merge pull request #6 from litixsoft/master

bugfixing in travis and readme
MongoSessionStore.all fix

I don't think cursor.each is synchronous, at least I didn't get it working.
Merge pull request #7 from Lexas/patch-1

MongoSessionStore.all fix
added memcached store
fix test
little fix
v0.4.1
another fix
v0.4.2
trigger travis
trigger travis
chore(session): sessionstore supports now express version 4
chore(session): sessionstore supports now express version 4