Fixes test_creating_hashes

* Learned that hashes have a class of Hash
* Learned that {} denotes an empty hash
* Learned that empty hashes have a size of 0

[#65851406]
Fixes test_hash_literals

* Learned that hashes are similar to arrays in
  that they have "elements" made up of
  name => value pairs
* Learned that the number of pairs are equivalent
  to the hash size

[#65851406]
Fixes test_accessing_hashes_with_fetch

* Learned that if you fetch a key that doesn't
  exist, you will get a KeyError
* It's better to use #fetch instead of #[] when
  accessing hash keys because it will return an
  error vs. just returning 'nil'

[#65851406]
Fixes test_changing_hashes

* Learned that you can change the value of a
  key => value pair by just accessing the hash
  key and assigning it a new value
* I'm not really sure why "expected" was broken
  out into a variable versus a literal because
  I'm not sure what a literal is. I will
  speculate that "expected" was a variable so
  that it could contain a hash so that it could
  be asserted equal to hash on line 40

[#65851406]
Fixes test_hash_is_unordered

* Learned that in terms of equivalency, the order
  of the key => value pairs is unimportant.
* I also confirmed that equivalency will check for
  both the keys and values being present and equal

[#65851406]
Fixes test_hash_keys

* I learned that hash key size is equivalent to
  the number of keys in the hash
* I learned that you can use the include? method
  to check for the presence of a key
* I also learned that all the keys in a hash have
  a class of array

[#65851406]
Fixes test_combining_hashes

* I learned that the .merge method will overwrite
  any existing key => value pairs and add new
  key => value pairs at the end of the hash it's
  being merged into (remembering that order really
  doesn't matter)

[#65851406]
Fixes test_default_value

* Learned that the .new method on a hash has an
  option of specifying the default value of any
  key where the value has not been specified

[#65851406]
Fixes test_default_value_is_the_same_object

* I learned that you can use an array as the
  default value of a new hash, populate that
  array, and then any comparison with a hash key
  that uses that array with another hash key that
  uses that array will declare them equal (same
  object_id)

[#65851406]
Fixes test_default_value_with_block

* A little confused here. I think I learned that
  when the hash and key are passed into this
  block, the value will be []. However, hash[:one]
  and hash[:two] were assigned array values of
  "uno" and "dos" respectively.

[#65851406]