Python Version Compatibility Bugs
### How did it happen?
1. Open existing Sketch file (5 pages with artboard + Symbols page) on Sketch 44 (41411)
2. Install the plugin
3. Select: Plugins > Git > Advanced > Generate files for pretty diffs


### Error log

```
Traceback (most recent call last):
  File "/Users/Petteri/Library/Application Support/com.bohemiancoding.sketch3/Plugins/Git 2.sketchplugin/getArtboardNames.py", line 15, in <module>
    name = pageName + "/" + artboardName
TypeError: can't concat bytes to str

```