Connection string does not parse hash character properly

[cypai]

• asyncpg version: 0.18.3
• PostgreSQL version: 11.5
• Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
  the issue with a local PostgreSQL install?: Reproduced locally
• Python version: 3.7.4
• Platform: macOS, Debian
• Do you use pgbouncer?: No
• Did you install asyncpg with pip?: Yes
• If you built asyncpg locally, which version of Cython did you use?: N/A
• Can the issue be reproduced under both asyncio and
  uvloop?: Didn't try yet

Similar issue to #429 . If the password includes a # character, you get the following error:
ValueError: invalid literal for int() with base 10:

The URI I was using looked like: postgresql://postgres:abcd&#[email protected]:5432/db, and psql parses it correctly.

When you remove the #, it works fine.

[cypai]

Hmm, looks like a different issue in the databases library. Will check there.