Update .gitignore to ignore log files. In particular npm-debug.log
Update .gitignore to ignore log files. In particular npm-debug.log

Change-Id: I0d6ae4543fa8003073c334a81443328b507543ad

google/data-transfer-project,google/data-transfer-project,google/data-transfer-project,google/data-transfer-project,google/data-transfer-project