[BUG]

**Describe the bug**

themes folder empty on Ubuntu 18.04

**To Reproduce**

install bashtop using
```
sudo add-apt-repository ppa:bashtop-monitor/bashtop
sudo apt update
sudo apt install bashtop
```
**Expected behavior**

Since the documentation says:
```
Themes
Bashtop now has theme support and a function to download missing local [themes](https://github.com/aristocratos/bashtop/blob/master/themes) from repository.

See themes folder for available themes.

The builtin theme downloader places the default themes in $HOME/.config/bashtop/themes. User created themes should be placed in $HOME/.config/bashtop/user_themes to be safe from overwrites.

```
I expect the folder "themes" to be populated with themes. Furthermore, if I try and change the theme in the .cfg:
```
#* Color theme, looks for a .theme file in "$HOME/.config/bashtop/themes" and "$HOME/.config/bashtop/user_themes"
#* Should be prefixed with either "themes/" or "user_themes/" depending on location, "Default" for builtin default theme
color_theme="Default"
```
substituing `default` with the name of a theme available here, bashtop overwrites that theme and places back "Default".
**Info (please complete the following information):**
- Bashtop version: 0.9.25
- (Linux) Linux distribution and version: Ubuntu 18.04.05 LTS
- Terminal used: bash
- Bash version: 4.4.20

contents of `$HOME/.config/bashtop/error.log`
```
New instance of bashtop version: 0.9.25 Pid: 9319

New instance of bashtop version: 0.9.25 Pid: 9509

New instance of bashtop version: 0.9.25 Pid: 9652

New instance of bashtop version: 0.9.25 Pid: 11794

New instance of bashtop version: 0.9.25 Pid: 11967
```