atom: 0.99.0 -> 0.129.0

[Bjørn Forsman: include fixupPhase, to fix this startup error on NixOS:
 $ ./result/bin/atom
 ./result/bin/atom: /nix/store/q3r5ww6pg5yb4j6p0d8inrhbgzmik0b6-atom-0.129.0/bin/.atom-wrapped: /bin/bash: bad interpreter: No such file or directory
]