How do I login to a Postgres database without a password?
When pg_hba.conf is checked for an authentication request, the first match determines the rule. 

Quote from the manual


  The first record with a matching connection type, client address, requested database, and user name is used to perform authentication. There is no “fall-through” or “backup”: if one record is chosen and the authentication fails, subsequent records are not considered


(Emphasis mine)

In your case the lines: 

host    all             all             127.0.0.1/32            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5


are matched before the trust lines you have added, therefor Postgres requires a password. If you want to disable password authentication completely you have to disable the md5 authentication, e.g. by commenting those lines.