Completed the first task of about_arrays.rb

* Pivotal Traker Id [#75411406]
* learned that an empty array is still in the class Array
* learend that the size of an empty array is 0
Completed task 2 of about_arrays.rb

* pivotal tracker id [#75411406]
* learned about array literals
* remembered that the << operator appends an element to an array. Horray!
completed task 3 of about_arrays.rb

* pivotal tracker id {#75411406}
* learned about accesing array elements by index
* arrays have a 0 based index
* negative indices count backwards from the end of the array
completed stage 4 of about_arrays.rb

* pivotal tracker id [#75411406]
* learned about slicing arrays
* arr[a,b] slices the array starting at index a and contain b elements
completed stage 5 of about_arrays.rb

* pivotal tracker id [#75411406]
* learned the difference between arrays and ranges
* ranges can be turned into arrays with .to_a
* (1..5) is different than (1...5)
* three dots will not include the last element (5)
completed stage 6 of about_arrays.rb

* pivotal tracker id [#75411406]
* learned how to slice an array with a range
* array[a..b] will slice the array from index a to index b
completed stage 7 of about_arrays.rb

* pivotal tracker id [#75411406]
* learned that .push(element) will append element to the array
* learned that .pop will return the last element of the array
* .pop will also permanantely remove the last element from the array
Completed all stages (8/8) of about_arrays.rb

* pivotal tracker id [#75411406]
* learned the shift and unshift are like pop and push
* but they operate on the first element of an array, not the last
Merge pull request #4 from glassbead0/75411406_about_arrays_master

about arrays master

[Delivers #75411406]