appSpecAssistant fails to run on Linux x86_64

When attempting to run appSpecAssistant in bash on Arch Linux running kernel 5.12.9-arch1-1, the executable fails. Details:

```
$ file -s appSpecAssistant
appSpecAssistant: Mach-O 64-bit x86_64 executable
```

```
$ ./appSpecAssistant validate --filepath appspec.yml --computePlatform lambda
bash: ./appSpecAssistant: cannot execute binary file: Exec format error
```

Googling around a bit seems to indicate that the executable ought to run on Mac, but won't run on Linux without Darling (a translation layer).

Any chance you could compile it for Linux and include that in your repo? Just a `go build` ought to do it.