find

• Usage: java gitlet.Main find [commit message]
• Description: Prints out the ids of all commits that have the given commit message, one per line. If there are multiple such commits, it prints the ids out on separate lines. The commit message is a single operand; to indicate a multiword message, put the operand in quotation marks, as for the commit command above.
• Runtime: Should be linear relative to the number of commits.
• Failure cases: If no such commit exists, prints the error message Found no commit with that message.
• Dangerous?: No
• Differences from real git: Doesn't exist in real git. Similar effects can be achieved by grepping the output of log.
• Our line count: ~15