Save Session forgets text type (resets to "Plain Text")

[dm-z]

First I've got to thanks author for this awesome package, witout it Atom is not usable for me.

Second I want to report a bug. Steps to reproduce:

1. Create new tab and start writing code (for me this was only tab I have)
2. Choose text type (I've chosen Objective-C for example)
3. Close Atom.
4. Open Atom.

SaveSession restores all the code, but it forgets that this was Objective-C code, so I have to choose text type manually every time. So if I don't save file with appropriate format it keeps restoring with "Plain Text".

OS X 10.11.1
Atom 1.0.19
save-session 0.15.7