[2.x] Fixes installation when using Herd

[nunomaduro]

This pull request fixes the installation of Octane (RoadRunner) when using something like Herd.

Before:

 Octane requires "spiral/roadrunner-http:^3.0.1" and "spiral/roadrunner-cli:^2.5.0". Do you wish to install them as a dependencies? (yes/no) [no]:
 > yes

Could not open input file: /Users/nunomaduro/Library/Application

After:

 Octane requires "spiral/roadrunner-http:^3.0.1" and "spiral/roadrunner-cli:^2.5.0". Do you wish to install them as a dependencies? (yes/no) [no]:
 > yes

./composer.json has been updated
Running composer update spiral/roadrunner-http spiral/roadrunner-cli --with-all-dependencies
Loading composer repositories with package information
...

[bnzo]

@nunomaduro I just saw your exchange here: roadrunner-server/roadrunner#1667

Would it be a solution to switch back to the php alias? As it was here: 5b52910

Maybe only use the php alias by checking if herd is installed as herd is setting up automatically the alias in the .zshrc file?