Submitting ProgrammingAssignment2

This commit includes changes to cachematrix.R
This file includes two main functions - makeCacheMatrix and cacheSolve.

makeCacheMatrix: This function creates a special "matrix" object that
can cache its inverse.
cacheSolve:            This function computes the inverse of the special
"matrix" returned by  makeCacheMatrix` above. If the inverse has already
been calculated (and the matrix has not changed), then the `cachesolve`
should retrieve the inverse from the cache.