Add standard charset to String conversion (FindBugs)
Add unit test for GelfCompressionEncoder
Increase FindBugs effort
GelfTransports#create() throws IllegalArgumentException if config invalid
Fix GelfMessage#hashCode()
GelfMessageJsonEncoder#encode should passthrough exceptions
Improve test coverage
Use a random machine identifier by default in GelfMessageChunkEncoder

The previous implementation was using the configured host name of the target server
and would fail if it was shorter than 4 characters. The current implementation
generates a random 4 bytes machine identifier if no other identifier (e. g. the
host name of the client) was provided. Only the first 4 bytes of the provided
machine identifier are being used and the rest is discarded.
Make all Logger instances static final
Add Maven JaCoCo plugin
Add coveralls-maven-plugin
Update Maven plugins to latest versions
Add organization info to POM
Update example in README.md
Add Travis CI and Coveralls badges