Cred leak fix

Merge pull request #83 from heroku/cd-log-shuttle-credential-no-leak

credential leak remediation

v0.16.0

• Restore batch.fill metrics

v0.15.0

• Simplified Makefile
• Various cleanups
• Separate kineses shard from logplex formater

v0.14.0

• Build with 1.6, move to vendor/
• Update dependencies
• Update .travis config to release docker images as well

v0.13.1

Build with 1.5.1

v0.13.0: Merge pull request #53 from heroku/fix_skip

Fix -skip-headers to not bomb out it with -input-format=rfc5424

v0.12.0

Update changelog

v0.11.0

Update Version number / release

v0.10.3: Add `msg.lost` to the emitted metrics.

This is similar to v0.9.X `alltime.lost` series metric

We were tracking it internally and intecting it into the log-stream,
just not tracking it in the metrics registry

v0.10.2: Explicitly default gzip to false

Before it defaulted to false because that is the zero value of bools in
Go. This is contrary to the rest of the lib (although that should be
revisited).

It also explicitly set to false in the flag parsing, which was different
than most other flags.