Code review updates:

Use a space between the both sides of operators.
Use a space between the method type: + / - and the type (void), (int) etc.
Properties should contain a space between @property and their attributes (nonatomic, strong).
Property attributes should start with their nonatomic or atomic attribute.
Methods should contain a space between their last parameter and the opening bracket (- (NSMutableArray *)cards { ) .
Merge pull request #1 from cyupa/master

Code review updates: