Put a verbose message in all drevops scripts if the required binaries are not available

[AlexSkrypnyk]

Examine all scripts in scripts/drevops for any binaries that are used and exit if they are not found

Example:

command -v curl >/dev/null || (fail "curl command is not available." && exit 1)

Example: https://github.com/drevops/drevops/blob/5f0c27c7fa6f936b2d039b12063ed503b942fead/scripts/drevops/notify-github.sh#L46

For multiple commands, consider using this:

for cmd in command_name1 command_name2 command_name3; do command -v ${cmd} >/dev/null || { echo "Command ${cmd} is not available"; exit 1; }; done