New version breaks 2.7 compatibility

[RufusVS]

Upon doing a full re-install of my software on a Raspberry Pi, I found my program
no longer works. My python code is backend for a html/php website, so it was a pain
to instrument and test down to the point of the problem. It turns out that the spawn init function
now uses Super().... which is incompatible with 2.0. Fortunately I found an old version of serial_spawn.py to verify this. Now I have two options, keep a copy of the old version around, or look at the proper pip function to grab prior version. I have mixed feelings of asking to have this "fixed" or just to have this issue as a cautionary message for those who use Python 2.7 still.