Fixes def test_symbols_are_symbols
through test_method_names_become_symbols. I learned:

* Identical symbols are equal, and their object ids are also equal.

* For def test_method_names_become_symbols, the methods
.all_symbols and .map and .to_s will display the string
"test_method_names_become_symbols"

[#65851846]
Fixes def test_constants_become_symbols
through def test_symbols_are_not_strings. I learned:

* Strings can me made to symbols

* Symbols can be made with spaces

* Symbols with include interpolaated strings.

* Strings can include interpolated symbols.

* A symbol is not a string.

[#65851846]
Fixes def test_symbols_do_not_have_string_methods
through def test_symbols_can_be_dynamically_created. I learned:

* Symbols can't have string characteristics like each_char or reverse.

* Test symbols can't be concatenated, but can be dynamically created.

* It's not a good idea to dynamically create a lot symbols because they take
up a lot of memory.

[#65851846]