Allows users to filter the Jenkins jobs shown in the widget by providing a regular expression in the config file. The regex should be specified in the config like so:
```
jobNameRegex: ^[a-z]+.$
```
Another example:
```
jobNameRegex^[a-z]+\[[0-9]+\]$
```
If, on startup, a widget's positional configuration is invalid (ie:
cannot be displayed onscreen) then terminate the app and inform about
which widget is erroring
