Problem 1344. Moving average (variable kernel length)

Find the moving average in a vector. The kernel length is a variable. For example

 x = 1:10
 kernel_length = 2 

would result in

 [ 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 ]

and

 x = 1:10
 kernel_length = 3 

would result in

 [ 2 3 4 5 6 7 8 9 ]