Always force curly braces for block statements

[okovpashko]

Currently, the config forces omitting curly braces for the one-line block statements:

if (shouldInvoke) { // error: Unnecessary { after 'if' condition.(curly)
  invoke();
}

To fix the error we must write the condition in the following way:

if (shouldInvoke)
  invoke();

I suggest forcing the curly braces even for one-line condition/loop bodies because they make the code easier to read and we get a more consistent code style.