New save output

Saving diffraction intensities into different file formats
@tacaswell,  I used it like that('wb'), but it is not working in Travis in Python 3.4 for lines 106-113 then I saw I can use 'wt' in Python 3.4 instead of 'wb' which solved that issue. 
Now I have an issue in line 118 , np.savetxt(f, np.c_[tth, intensity], newline='\n'), in Python 3.4