handling invalid section name

[mikeiannacone]

The driver should confirm that the given config section name is valid, before using it. Currently, an invalid section name gives the error below.

Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.simontuffs.onejar.Boot.run(Boot.java:340)
    at com.simontuffs.onejar.Boot.main(Boot.java:166)
Caused by: java.lang.NullPointerException
    at gov.pnnl.stucco.utilities.Replayer.<init>(Replayer.java:39)
    at gov.pnnl.stucco.utilities.CollectionDriver.main(CollectionDriver.java:66)
    ... 6 more
Exception in thread "Thread-0" java.lang.ExceptionInInitializerError
    at gov.pnnl.stucco.utilities.CollectionDriver$1.run(CollectionDriver.java:52)
Caused by: java.lang.IllegalStateException: Shutdown in progress
    at java.lang.ApplicationShutdownHooks.add(ApplicationShutdownHooks.java:66)
    at java.lang.Runtime.addShutdownHook(Runtime.java:211)
    at org.mapdb.EngineWrapper$CloseOnJVMShutdown.<init>(EngineWrapper.java:581)
    at org.mapdb.DBMaker.makeEngine(DBMaker.java:764)
    at org.mapdb.DBMaker.make(DBMaker.java:665)
    at gov.pnnl.stucco.utilities.CollectorMetadata.getLatestFromDb(CollectorMetadata.java:65)
    at gov.pnnl.stucco.utilities.CollectorMetadata.<init>(CollectorMetadata.java:54)
    at gov.pnnl.stucco.utilities.CollectorMetadata.<clinit>(CollectorMetadata.java:26)
    ... 1 more

An example of this can be caused by: java -jar ./collectors/target/collect.jar -load -config ./collectors/config/collectors.yml -section asdf