Add workaround for https://github.com/rails/spring/pull/484

config/initializers/spring.rb

+if Rails.env.development? || Rails.env.test?
+  Thread.abort_on_exception = false
+  Thread.send(:define_method, :abort_on_exception) do |value|
+    puts "Ignoring Thread.abort_on_exception change to #{value}"
+  end
+end