Adds more specific error exception checks to tests

spec/jdbc_spec_helper.rb

@@ -15,7 +15,7 @@ RSpec.shared_context 'when initializing' do
   it 'shouldn\'t register with a missing jar file' do
     jdbc_settings['driver_jar_path'] = nil
     plugin = LogStash::Plugin.lookup('output', 'jdbc').new(jdbc_settings)
-    expect { plugin.register }.to raise_error
+    expect { plugin.register }.to raise_error(LogStash::ConfigurationError)
   end
 end
 
@@ -64,8 +64,6 @@ RSpec.shared_context 'when outputting messages' do
   it 'should save a event' do
     expect { plugin.multi_receive([event]) }.to_not raise_error
 
-    sleep 5
-
     # Verify the number of items in the output table
     c = plugin.instance_variable_get(:@pool).getConnection
     stmt = c.prepareStatement("select count(*) as total from #{jdbc_test_table} where message = ?")