combine similar test drivers

We should combine the following drivers:
```chef_phasta_adaptLoop_posix.cc``` and ```chef_phasta_sam_adaptLoop_sz_posix.cc``` and 

```chef_phasta_adaptLoop_ramdisk.cc``` and ```chef_phasta_sam_adaptLoop_sz_ramdisk.cc```

```chef_phasta_adaptLoop.cc``` and ```chef_phasta_sam_adaptLoop_sz.cc```