Fix coverage

.simplecov

@@ -1,8 +1,10 @@
 require 'coveralls'
 
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new([
   SimpleCov::Formatter::HTMLFormatter,
   Coveralls::SimpleCov::Formatter,
-]
+])
 
-SimpleCov.start { add_filter '/spec/' }
+SimpleCov.start do
+  add_filter '/spec/'
+end

Gemfile

@@ -5,4 +5,4 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in lita-tox.gemspec
 gemspec
 
-gem 'coveralls', require: false
+gem 'coveralls', group: :test, require: false

spec/spec_helper.rb

@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# This should be on the top of the file
+# This should be on the top of the file.
 require 'simplecov'
 
 # rubocop:disable Style/BlockComments