Complete except inefficient karatsuba

[Falieson]

 PASS  Chapter1/mergeSort.test.js
  mergeSort
    ✓ merges two arrays (8ms)
    ✓ sort a large array (10,000) (208ms)
    ✓ sort a big array (100,000) (165ms)

 PASS  Chapter1/secondLargestNumber.test.js
  secondLargestNumber
    ✓ smallest array (14ms)
    ✓ small array (8) (1ms)
    ✓ large array (1,000) (9ms)
    ✓ inefficient: FAILS on big array (5000) (39ms)
  yieldSecondLargestNumber
    ✓ smallest array (2ms)
    ✓ small array (8) (1ms)
    ✓ large array (1,000) (26ms)
    ✓ inefficient: FAILS on big array (5,000) (133ms)

 PASS  Chapter1/insertionSort.test.js
  insertionSort
    ✓ sorts a small array (8ms)
    ✓ sorts a large array (301ms)

 FAIL  Chapter1/karatsubaMultiply.test.js
  karatsubaMulti1
    ✓ small x=1000, y=1000 (3ms)
    ✓ large x=1000000, y=1000000 (1ms)
    ✕ big x.length === 64 === y.length (11ms)
  karatsubaMulti2
    ✓ small x=1000, y=1000 (1ms)
    ✓ large x=1000000, y=1000000
    ✕ big x.length === 64 === y.length (2ms)

Help: https://stackoverflow.com/questions/50556069/karatsuba-multiplcation-of-large-numbers-fails-in-javascript

[Falieson]

Add Library https://github.com/peterolson/BigInteger.js

[Falieson]

Test Suites: 4 passed, 4 total
Tests:       23 passed, 23 total
Snapshots:   0 total
Time:        1.542s
----
 PASS  Chapter1/karatsubaMultiply.test.js
  karatsubaMultiply
    ✓ small x=1000, y=1000 (8ms)
    ✓ large x=1000000, y=1000000 (1ms)
    ✓ FAILS: big NUMBER x.length === 64 === y.length (1ms)
    ✓ big STRING x.length === 64 === y.length (108ms)
  karatsubaMulti1
    ✓ small x=1000, y=1000
    ✓ large x=1000000, y=1000000
    ✓ FAILS: big x.length === 64 === y.length (1ms)
  karatsubaMulti2
    ✓ small x=1000, y=1000
    ✓ large x=1000000, y=1000000 (1ms)
    ✓ FAILS: big x.length === 64 === y.length

 PASS  Chapter1/mergeSort.test.js
  mergeSort
    ✓ merges two arrays (3ms)
    ✓ sort a large array (10,000) (101ms)
    ✓ sort a big array (100,000) (76ms)

 PASS  Chapter1/insertionSort.test.js
  insertionSort
    ✓ sorts a small array (2ms)
    ✓ sorts a large array (141ms)

 PASS  Chapter1/secondLargestNumber.test.js
  secondLargestNumber
    ✓ smallest array (2ms)
    ✓ small array (8)
    ✓ large array (1,000) (4ms)
    ✓ inefficient: FAILS on big array (5000) (16ms)
  yieldSecondLargestNumber
    ✓ smallest array (2ms)
    ✓ small array (8) (1ms)
    ✓ large array (1,000) (10ms)
    ✓ inefficient: FAILS on big array (5,000) (71ms)