[lecture] step1 Red

make MyArray, use Test::Unit.
step1 only define empty?, not implement
step2 fake it
step3
step4 empty? is implement
[exercise] step1 make MyStack class
step2 fake it
step3 red
step3 fake it
step4 red
step4 green
step5 green
step6 red
step6 green
step7 red
step7 green
step8 green
Merge branch 'rubykansai/58/beginner_lesson_of_TestUnit'