replace stubs with allow receive in from_builder_spec
replace stubs with allow receive in layout_spec
remove MiniTest::Assertion definition from Ruby 1.8
Merge pull request #3224 from timoschilling/remove_stubs

Remove stubs
Merge pull request #3225 from timoschilling/remove_ruby_1_8_code

remove MiniTest::Assertion definition from Ruby 1.8
restyle layout_spec.rb

also: removed any stubs that weren’t needed for the tests to pass
fixing a typo