Setup coverage check (and tidy up ignore files)

.gitignore

@@ -2,4 +2,5 @@
 config/pipeline.yml
 .DS_Store
 tmp/*
-opt/
+opt/*
+coverage/*

Gemfile

@@ -6,6 +6,8 @@ gem "propono"
 gem "rugged"
 gem 'aws-sdk-ecr'
 
+gem 'simplecov', require: false, group: :test
+
 group :development, :test do
   # gem "bundler"
   gem "rake"

Gemfile.lock

@@ -25,9 +25,11 @@ GEM
     aws-sigv4 (1.1.0)
       aws-eventstream (~> 1.0, >= 1.0.2)
     concurrent-ruby (1.1.5)
+    docile (1.3.2)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     jmespath (1.4.0)
+    json (2.2.0)
     mandate (0.2.0)
     metaclass (0.0.4)
     minitest (5.11.3)
@@ -38,6 +40,11 @@ GEM
       aws-sdk-sqs
     rake (12.3.3)
     rugged (0.28.2)
+    simplecov (0.17.0)
+      docile (~> 1.1)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.2)
     thread_safe (0.3.6)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
@@ -54,6 +61,7 @@ DEPENDENCIES
   propono
   rake
   rugged
+  simplecov
 
 BUNDLED WITH
    1.17.2

test/test_helper.rb

@@ -1,6 +1,9 @@
 ENV["env"] = "test"
-
 gem "minitest"
+
+require 'simplecov'
+SimpleCov.start
+
 require "minitest/autorun"
 require "minitest/pride"
 require "minitest/mock"