Lmdb Error of not having enough disk space size.

[rajatkb]

Figured that since the code was giving a possible of max 1TB so reduced it to a GB and it worked
So i have included this in the code

def write(self, images, labels = [] , max_data_map_size=1073741824):
      ## code ##  
      env = lmdb.open(self._lmdb_path, map_size = max(max_data_map_size, images.nbytes))
      ## atleast this will give a bit of flexibility

[davidstutz]

Sounds reasonable, didn't think about that. Feel free to make a PR for that ;)