Depend on chefspec 3.1.0.beta.1
port to chefspec3.1
Make rubocop happy.
adopt required chefspec version
Adopt the multi_environment_monitoring

One could use the multi_environment_monitoring-parameter to be [false, true, array_of_string]. When its false, only the own environment is searched. When its true, all environments are searched. And when its a list of environment-names, the named environments are searched.
make rubocop happy
Incorporate most of sethvargos comments

 - depend on chefspec ~>3.1 instead of ~>3.1.0
 - simplify the preparation of the runner in server_spec.rb
 - linebreaks for server_spec.rb
 - improve the template and service tests in client_spec.rb
Update README.md

Add a list of allowed values to the attributes description and a bigger piece of text to the usage section to describe what multi_environment_monitoring can be used for.
Merge pull request #28 from bcs-de/chefspec-3.1

Chefspec 3.1
Merge pull request #32 from bcs-de/feature/extend_multi_environment_monitoring

Extend multi environment monitoring
Bumping for 1.4.2