# Apply gravity to this matrix

This was inspired by [this question][1].
Given an \$m\times n\$ matrix of \$0\$'s and \$1\$'s, apply "gravity" to it. This means to drop down all the \$1\$'s as if they were affected by gravity. 

For example

    [[1,0,1,1,0,1,0]
     [0,0,0,1,0,0,0]
     [1,0,1,1,1,1,1]
     [0,1,1,0,1,1,0]
     [1,1,0,1,0,0,1]]
Should result in

    [[0,0,0,0,0,0,0]
     [0,0,0,1,0,0,0]
     [1,0,1,1,0,1,0]
     [1,1,1,1,1,1,1]
     [1,1,1,1,1,1,1]]

As all \$1\$'s have been dropped down.

Input will be atleast \$1\times 1\$. You may take input in all reasonable forms (Bitsets, arrays, Lists) and either output the result, return a new Bitset, array or list or simply modify the input. 

This is code golf, so the answer with the fewest bytes wins!

More test-cases:

    [[1,0]                   [[0,0]
     [0,0]            ->      [1,0]
     [1,0]]                   [1,0]]
    
    [[1,1,1,1,1]            [[1,0,1,1,0]
     [1,0,1,1,0]      ->     [1,1,1,1,0]
     [1,1,1,1,0]]            [1,1,1,1,1]]
    
    [[1]]             ->    [[1]]


  [1]: https://codegolf.stackexchange.com/questions/235446/neural-processing-lattice-checker