Publish and respond to bridge/config/devices/get

[jjrh]

Regarding: #1305

• When sent a empty payload to bridge/config/devices/get , publish to
  'bridge/config/devices'
• For bridge/config/devices & bridge/config/devices/get only ever
  publish to the corresponding topic if a empty payload is sent.
• Make sure devicesPublish doesn't treat messages to
  bridge/config/devices/get as a zigbee device.

[jjrh]

Build failing due to signature verification when getting packages.

Err:81 https://packagecloud.io/github/git-lfs/ubuntu trusty InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6B05F25D762E3157
Get:110 https://packagecloud.io/computology/apt-backport/ubuntu trusty/main amd64 Packages [3,628 B]
Get:111 https://packagecloud.io/rabbitmq/rabbitmq-server/ubuntu trusty/main amd64 Packages [7,382 B]
Get:112 https://packagecloud.io/rabbitmq/rabbitmq-server/ubuntu trusty/main i386 Packages [7,382 B]
Fetched 38.9 MB in 4s (9,721 kB/s)
Reading package lists... Done
W: http://ppa.launchpad.net/couchdb/stable/ubuntu/dists/trusty/Release.gpg: Signature by key 15866BAFD9BCC4F3C1E0DFC7D69548E1C17EAB57 uses weak digest algorithm (SHA1)
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packagecloud.io/github/git-lfs/ubuntu trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6B05F25D762E3157
W: Failed to fetch https://packagecloud.io/github/git-lfs/ubuntu/dists/trusty/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6B05F25D762E3157
E: Failed to fetch http://us-east-1.ec2.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/source/Sources.gz  Hash Sum mismatch
E: Failed to fetch http://us-east-1.ec2.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-amd64/Packages.gz  Hash Sum mismatch
E: Failed to fetch http://us-east-1.ec2.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-i386/Packages  Writing more data than expected (499649 > 499536)
W: Some index files failed to download. They have been ignored, or old ones used instead.
The command "sudo apt update -y" failed and exited with 100 during .
Your build has been stopped.

[Koenkk]

There are some linting errors now, could you fix them? (https://travis-ci.org/Koenkk/zigbee2mqtt/builds/511604280?utm_source=github_status&utm_medium=notification)

[Koenkk]

Thanks!