Staircase

Consider a staircase of size 4

```
   #
  ##
 ###
####
```
Observe that its base and height are both equal to 4, and the image is drawn using `#` symbols and spaces.
The last line is not preceded by any spaces.

Write a function that given `N`, prints the staircase of size `N`.
e.g 

If N = 6 

The output is 

```
     #
    ##
   ###
  ####
 #####
######
```