Add cider repl plugin
Exercise 1.9
Exercise 1.10
Factorial examples
Fibonacci examples
Counting change example
Exercise 1.11
Removed code duplication in tests for examples
Exercise 1.12
Exercise 1.14
Exercise 1.15
Examples 1.2.4
Exercise 1.16
Exercise 1.16 - correct comment
Exercise 1.17
Exercise 1.18
Exercise 1.19
Added namespace
Use zero based index
Exercise 1.20