Release 1.4.0

• Fix example (f589898)
• Small README change (e56a3e3)
• Fix linting (c0b5f51)
• Update README with new return value (c1b348d)
• Add a test about huge combinations (a75a371)
• Add a test about iterables (3e4d7c7)
• Use cartesianIterate() (e188d3b)
• Refactoring (5e2a023)
• Upgrade fast-cartesian 1.2.0 -> 1.3.0 (0a7e062)