Unexpected changes after pull
## Description
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Provide a detailed description of the behavior you're seeing or the behavior you'd like to see **below** this comment.
-->

Unexpected JSON changes happens after pull commits from remote. and kactus freezes due to massive changes.

## Version
* Kactus: 0.3.5
* Operating system: macOS 10.13.4

## Steps to Reproduce
It happens every time after I pull new commits and open auto-generated sketch file. 
You can check this issue with video below.

0. quit Kactus
1. hard reset to older commits using terminal
2. open Kactus, delete & regenerate sketch files. (Sketch files is fine at this point)
3. quit and restart kactus.
4. pull latest commits using Kactus
5. open generated sketch file.
6. can find sketch file is corrupted
7. Kactus tries to make changes and throws error.

It works fine when I
1. move to latests commit 
2. delete & regenerate sketch files

### Expected Behavior
There shouldn't be no JSON changes right after pulling.

### Actual Behavior
massive JSON changes happen && file is corrupted

## Additional Information

I uploaded commits to my private repo `tsingtao` which I shared before.
you can reproduce this by rewinding to `ae18baf` and doing these steps above.

You can check unexpected change issue with [this video](https://www.dropbox.com/s/pat8oueosjeby5j/unwantedchanges.mov?dl=0).

Kactus Error
![2018-04-23 1 51 19](https://user-images.githubusercontent.com/1055213/39107470-6e7cdea8-46fd-11e8-904d-dc89eb4ae73d.png)

Massive unexpected changes.
<img width="914" alt="2018-04-23 1 53 49" src="https://user-images.githubusercontent.com/1055213/39107517-c7f0fadc-46fd-11e8-84cc-f925f6941842.png">

### Logs
Console logs
[console.log](https://github.com/kactus-io/kactus/files/1936696/console.log)

Kactus Logs
[2018-04-23.kactus.production.log](https://github.com/kactus-io/kactus/files/1936700/2018-04-23.kactus.production.log)
