test => valid phone number
test => invalid phone number type
test => must separate type with retains using whitespace
test => must retains number separate by -
test => invalid phone number length
test => phone number must start (###)
Merge branch 'valid_phone_number' into master
add test into all-tests.html
test => sum
test => average
test => even
test odd
refactoring => remove code duplication
test => square
test => cube
fix bug => avarage empty array will return NaN
Merge branch 'array_helpers' into master
add test into all-tests.html