Janus produces warnings yet the guide suggests none will occur

# User role

Evaluating user
# Trying to achieve

Attempting to follow the getting started guide that offers to help with evaluation so I can gain intuitions about what JanusGraph can do, how to interact with it usefully, and the costs of managing its infrastructure all of which I'm attempting to do in order to avoid excluding it as a useful tooling choice.
# Steps to reproduce

Follow the guide at http://docs.janusgraph.org/latest/server.html#server-getting-started
# Expected outcome

Output as listed in the guide
# Actual outcome

```
$ bin/gremlin.sh

\,,,/
(o o)
-----oOOo-(3)-oOOo-----
plugin activated: janusgraph.imports
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/tristan/Downloads/janusgraph-0.2.0-hadoop2/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/tristan/Downloads/janusgraph-0.2.0-hadoop2/lib/logback-classic-1.1.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
12:39:38 WARN org.apache.hadoop.util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
plugin activated: tinkerpop.hadoop
plugin activated: tinkerpop.spark
plugin activated: tinkerpop.tinkergraph
```
# Other info

```
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 17.10
Release: 17.10
Codename: artful
```

strace log produced after re-running gremlin.sh with strace -os.log -e file,process -f -- ...: [s.log](https://github.com/JanusGraph/janusgraph/files/1935592/s.log)

Start with the server getting-started guide and the bin/gremlin.sh startup output shown in the report. Compare the documented output with the SLF4J binding and Hadoop native-library warnings, then determine whether the guide or startup dependencies need clarification. Done means the guide accurately describes the warnings produced during startup.

Written by the indexing model from the issue text.