casm super --get-transf-mat returns the identity matrix

`casm super --scelnames "SCEL...." --get-transf-mat --unitcell "SCEL1_1_1_1_0_0_0"` always returns the identity matrix regardless of the scel selected. Also, if it is called without a unitcell, it crashes

```
casm super --scelnames "SCEL1_1_1_1_0_0_0" --get-transf-mat

CASM: Uncaught exception: 
std::bad_alloc
```