Fixed failing test in about_asserts.rb

[65851826]

* Learned that the assert method simply asks if the argument passed is true.
* Learned that assert has a second optional argument that contains additional information to help figure out why the test is failing.
Fixed line 21, test_assert_equality: made expected_value = 2
[65851830]

*Learned that test_assert_equality tests to see if an expect value is equal to an actual value.
Committing additional changes to about_asserts.rb. Not sure I did anything substantive, but want to submit anyways.
[65851826]