Remove some unnecessary rules

[dinhhoanglong91]

• [x] Consider MultiLineNotAllowed as warning
• [x] Remove Squiz.WhiteSpace.FunctionClosingBraceSpace because we don't add blank line before closing brace
• [x] Remove FunctionSpacing because it doesn't handle closing brace of the last function in a class
• [x] Remove ObjectOperatorSpacing because sometimes we need space before -> (Check example below)
• [x] Remove SemicolonSpacing because sometime we write ; in new line (Check example below)

$user = $this->userRepository
    ->where('name', 'foo')
    ->get()
;