Render "git diff" output better (#485)
Render "git diff" output better (#485)

Previously it prints out stuff like:

`git diff output:
	stdout:[105 110 116 101 103 114 97 116 105 111 110 95 116 101 115 116 47 82 69 65 68 77 69 46 109 100 10 105 110 116 101 103 114 97 116 105 111 110 95 116 101 115 116 47 97 103 101 110 116 115 47 97 103 101 110 116 115 46 103 111 10 105 110 116 101 103 114 97 116 105 111 110 95 116 101 115 116 47 103 99 101 47 103 99 101 95 116 101 115 116 105 110 103 46 103 111 10 105 110 116 101 103 114 97 116 105 111 110 95 116 101 115 116`
GoogleCloudPlatform/ops-agent,GoogleCloudPlatform/ops-agent