message: remove usages of the old try! macro
  This caused a warning when building on nightly, and thus a CI failure.
diff: @@ -110,7 +110,7 @@ where
  // L_1_1 x1 = b_1 - x0*l_1_0
  for (col_ind, col) in lower_tri_mat.outer_iterator().enumerate() {
  - try!(lspsolve_csc_process_col(col, col_ind, rhs));
  + lspsolve_csc_process_col(col, col_ind, rhs)?;
  }
  Ok(())
  }
  @@ -339,7 +339,7 @@ where
  for &ind in dstack.iter_right().map(stack::extract_stack_val) {
  println!("ind: {}", ind);
  let col = lower_tri_mat.outer_view(ind).expect("ind not in bounds");
  - try!(lspsolve_csc_process_col(col, ind, x_workspace));
  + lspsolve_csc_process_col(col, ind, x_workspace)?;
  }
  Ok(())
  }
  