Bumps version to 3.0.19

Now depends on billiard 2.7.3.27

Bumps version to 3.0.17

Removes print statement

Bumps version to 3.0.15 and updates Changelog

Tests passing

Now depends on Kombu 2.5.4

Fixes typo in daemonizing tutorial. Closes celery#1055

Fixes tests

Bumps version to 3.0.10 and updates Changelog