Shared Text Styles can be updated, but no synchronisation happens in the files

### Description

Shared Text Styles files can be updated, but no synchronisation happens across the Sketch files 

### Version 


**Kactus version:** 0.2.10
**OS version:** OS SIerra 10.12.5

### Steps to Reproduce

1. Set the Kactus settings for Sharing Text and Layer Styles
1. Get a file with Text Styles
1. Create a new file from Kactus: the Styles are inherited
1. Modify the Text Styles into a Sketch File
1. Open another file: the Styles modifications aren't reflected

<!--

If the issue involves a specific public repository, including the information
about that repository will make it is easier to recreate the issue.

If you think screenshots or a GIF recording will help demonstrate the issue
better, feel free to add them here.

-->

**Expected behavior:** 
When I change a Style in a Sketch file, I expect that the other files inherit from these modifications
**Actual behavior:** 
No Styles synchronisation

**Reproduces how often:** 100%
### Logs

<!--

There may be some relevant information in log files generated by Kactus:

 - If you are on macOS, attach the most recent log file from:
   `~/Library/Application Support/Kactus/logs/*.kactus.production.log`
 - If you are on Windows, attach the most recent log file from:
   `%APPDATA%\Kactus\logs\*.kactus.production.log`

The log files are organized by date, so see if anything was generated for
today's date.

-->

#### Additional Information

<!--

Any additional information, configuration or data that might be necessary to
reproduce the issue.

If you are dealing with a performance issue or regression, attaching a
[Timeline profile](https://github.com/kactus-io/kactus/blob/master/docs/contributing/timeline-profile.md)
of the task will help the developers understand the runtime behaviour of the
application on your machine.

-->
