Fix for the issue of tmp dir with capital letters
Fix for the issue of tmp dir with capital letters

Some might be wondering how this fixes it. The problem is that that
`.downcase` is downcasing the full path, including the directory and
the file name.

Later on, it tries to retrieve the file from a different path, and the
file is not there.

What sense does it have to downcase a filename? Actually no sense:
table name normalization is taken care of in other parts of the code,
and we can afford the original file names with or without caps.

CartoDB/cartodb,CartoDB/cartodb,CartoDB/cartodb,CartoDB/cartodb,CartoDB/cartodb