Update logging format to align messages

[mogren]

Description of changes:
Use a tab instead of a space after the log level. Example of log output:

2019-05-16T19:31:39Z [DEBUG]	Discovered ENI eni-053402f8bf3d6c1a7, trying to set it up
2019-05-16T19:31:39Z [DEBUG]	DataStore Add an ENI eni-053402f8bf3d6c1a7
2019-05-16T19:31:39Z [INFO]	Synced successfully with APIServer
2019-05-16T19:31:39Z [INFO]	Add/Update for Pod cni-metrics-helper-688f4747cf-chvvm on my node, namespace = kube-system, IP = 172.31.2.95
2019-05-16T19:31:39Z [INFO]	Add/Update for Pod coredns-7d77776957-hmj5p on my node, namespace = kube-system, IP = 172.31.3.20
2019-05-16T19:31:39Z [INFO]	Add/Update for CNI pod aws-node-p6htp
2019-05-16T19:31:39Z [INFO]	Add/Update for CNI pod aws-node-gp6j4
2019-05-16T19:31:39Z [INFO]	Add/Update for CNI pod aws-node-rqz2m
2019-05-16T19:31:39Z [INFO]	Add/Update for Pod coredns-7d77776957-cdpsc on my node, namespace = kube-system, IP = 172.31.10.37
2019-05-16T19:31:39Z [DEBUG]	Adding ENI(eni-053402f8bf3d6c1a7)'s IPv4 address 172.31.10.110 to datastore
2019-05-16T19:31:39Z [DEBUG]	IP Address Pool stats: total: 0, assigned: 0
2019-05-16T19:31:39Z [INFO]	Added ENI(eni-053402f8bf3d6c1a7)'s IP 172.31.10.110 to datastore
2019-05-16T19:31:39Z [DEBUG]	Adding ENI(eni-053402f8bf3d6c1a7)'s IPv4 address 172.31.3.254 to datastore
2019-05-16T19:31:39Z [DEBUG]	IP Address Pool stats: total: 1, assigned: 0
2019-05-16T19:31:39Z [INFO]	Added ENI(eni-053402f8bf3d6c1a7)'s IP 172.31.3.254 to datastore
2019-05-16T19:31:39Z [DEBUG]	Adding ENI(eni-053402f8bf3d6c1a7)'s IPv4 address 172.31.2.149 to datastore
2019-05-16T19:31:39Z [DEBUG]	IP Address Pool stats: total: 2, assigned: 0
2019-05-16T19:31:39Z [INFO]	Added ENI(eni-053402f8bf3d6c1a7)'s IP 172.31.2.149 to datastore
2019-05-16T19:31:39Z [INFO]	ENI eni-053402f8bf3d6c1a7 set up.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.