Skip to raise ::DependencyError in phantomjs#run
Skip to raise ::DependencyError in phantomjs#run

if given block returns nil, $?.success will produce
```
  undefined method `success?' for nil:NilClass (NoMethodError)
```

given command:
```
teaspoon -C default
```

bouk/teaspoon,bouk/teaspoon,modeset/teaspoon,bouk/teaspoon,modeset/teaspoon,modeset/teaspoon