Remove PWD from provenance env

[ianlewis]

Updates #822

Remove PWD from the environment variables in provenance build steps as it is redundant with the given working directory. PWD is set when executing the command but is not included in the environment variables that are added to the buildConfig in the provenance.

Before:

"steps": [
    {
        "command": ["bash", "-c", "echo $STEP2"],
        "env": [
            "STEP2=fuga",
            "PWD=/home/user"
        ],
        "workingDir": "/home/user"
    },
    ...
]

After:

"steps": [
    {
        "command": ["bash", "-c", "echo $STEP2"],
        "env": [
            "STEP2=fuga"
        ],
        "workingDir": "/home/user"
    },
    ...
]

Signed-off-by: Ian Lewis ianlewis@google.com

[asraa]

LGTM -- CommandRunner contains posixEnv for Env but the CommandStep will render env without it for now. I see

[ianlewis]

LGTM -- CommandRunner contains posixEnv for Env but the CommandStep will render env without it for now. I see

Yes. I think we should set the variable but the question is whether it needs to be included in the provenance.