Stop when shelling out fails

Signed-off-by: Michael Maximilien <maxim@us.ibm.com>
Switch back to latest, vanilla Heroku nodjs buildpack

[#63634414]

Signed-off-by: Michael Maximilien <maxim@us.ibm.com>
Only save logs after crash

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Fix unit tests

Signed-off-by: Phan Le <ple@pivotallabs.com>
Copy the contents of logs folder only (not the logs folder itself)
Fix test that failed within a vagrant VM

Signed-off-by: Phan Le <ple@pivotallabs.com>
Auto-merge remote-tracking branch 'upstream/master'