Fixes test_creating_arrays

* It seems the class of a new Array is equal to
  the Array class

[#65851402]
Fixes test_creating_arrays at line 7

* New empty arrays have a size of 0

[#65851402]
Fixes test_array_literals for AboutArrays class

* Learned that a new array has an empty set
* Learned that arrays start with an index of 0
* Learned that specifying an index number of an
  array and specifying a value like will give
  that array item that value, like so:
  array[0] = 1

[#65851402]
Fixes test_accessing_array_elements

* I learned that there are many ways to access
  the same element in an array
* You can access an element using an index number
  like so: array[0] = the first element
* You can also access an element using methods
  on the array object like so:
  array.first = the first element
* You can also access array elements using a
  negative index number. This goes backwards
  through the array.

[#65851402]
Fixes test_slicing_arrays

* I learned that slicing is different from
  indexing.
* Indexing allows you to access specific elements
* Slicing accesses the "spaces" between the
  elements in an array
* So, array[4,0] starts in the array in that it
  accesses the last "space" after :jelly and ends
  outside the array
* There are no elements or "spaces" of 5, so
  array[5,0] doesn't exist, hence nil

[#65851402]
Fixes test_arrays_and_ranges

* I learned that Ranges and Arrays are NOT equal
* I learned that Range objects specified with 2
  periods are inclusive, while Range objects with
  3 periods excludes the last element

[#65851402]
Fixes test_slicing_with_ranges

* Learned that arrays using three periods exclude
  the last element
* Learned that arrays with negative numbers
  specified at the end point to the right-most
  array element and go from right to left

[#65851402]
Fixes test_pushing_and_popping_arrays

* I learned that push adds an element to the end
  of an array.
* I learned that "popping" an array will remove
  the last element in the array and you can store
  the value of that element in a variable

[#65851402]
Fixes test_shifting_arrays

* I learned that unshifting a value on an array
  adds that value as the first element in an array
* I learned that shifting a value from an array
  will remove that value from the front of an
  array and can be stored in a variable

[#65851402]