Fix for lucene-cli appsettings.json required error + installation/run tests (See #453)

[NightOwl888]

See #453.

This fixes the appsettings.json to make it optional and also adds a default appsettings.json to demonstrate the default settings that are available.

appsettings.json

{
  "egothor": { "stemmer": { "encoding": "UTF-8" } },
  "benchmark": { "work": { "dir": "work" } }
}

Note that egothor:stemmer:encoding can be set on the command line already, this is the default setting if no value is supplied. benchmark:work:directory can be supplied in a benchmark definition file and this is the default if it is not provided.

This serves as temporary documentation until #307 is completed.

Also, basic tests to install and run lucene-cli were added to ensure it can be installed and run without errors.