Small utility for exiting a long running shell command when a line in stdout matches a given regex.
When an early exit occurs, this util returns a `0` exitCode. Otherwise, it respects the output of the child command.
This utility forwards both `stderr` and `stdout` from the child command.
```bash
until_regex REGEX COMMAND [COMMAND_OPT, ...]
until_regex '^Ld .* MyApp' xcodebuild -workspace MyApp.xcworkspace -scheme MyApp clean build
```
MIT