Add more flexibility to user identify methods

[miguelcma]

Previously supported methods:

-(void)identifyUser;
-(void)identifyUserWithIdentifier:(NSString *)identifier;
-(void)identifyUserWithIdentifier:(NSString *)identifier attributes:(NSDictionary *)attributes;
-(void)identifyUserWithIdentifier:(NSString *)identifier attributes:(NSDictionary *)attributes location:(CLLocation *)location;

Added methods, to set attributes and location on auto identified users:

-(void)identifyUserWithAttributes:(NSDictionary *)attribute;
-(void)identifyUserWithAttributes:(NSDictionary *)attributes location:(CLLocation *)location;