Fix pending specs for exceptional isolation behavior

lib/mutant/runner.rb

@@ -186,8 +186,8 @@ module Mutant
       end
     rescue Isolation::Error => exception
       Result::Test.new(
-        test:     nil,
-        mutation: nil,
+        test:     test,
+        mutation: mutation,
         runtime:  Time.now - time,
         output:   exception.message,
         passed:   false

spec/unit/mutant/runner_spec.rb

@@ -95,12 +95,11 @@ RSpec.describe Mutant::Runner do
       Mutant::Result::Env.new(
         env:             env,
         runtime:         0.0,
-        done:            false,
         subject_results: expected_subject_results
       )
     end
 
-    pending 'on normal execution' do
+    context 'on error free execution' do
       subject { object.result }
 
       its(:env) { should be(env) }
@@ -110,7 +109,7 @@ RSpec.describe Mutant::Runner do
       end
     end
 
-    skip 'when isolation raises error' do
+    context 'when isolation raises error' do
       subject { object.result }
 
       its(:env)             { should be(env)                       }