shellcheck?

[ben-b-ow]

shellcheck raises a few minor issues -- thoughts about #27 ?

$> shellcheck --format gcc entrypoint.sh
entrypoint.sh:21:15: note: Use $(...) notation instead of legacy backticks .... [SC2006]
entrypoint.sh:23:15: note: Use $(...) notation instead of legacy backticks .... [SC2006]
entrypoint.sh:23:21: note: Double quote to prevent globbing and word splitting. [SC2086]
entrypoint.sh:23:36: note: Consider using grep -c instead of grep|wc -l. [SC2126]
entrypoint.sh:31:16: note: Use $(...) notation instead of legacy backticks .... [SC2006]
entrypoint.sh:31:22: note: Double quote to prevent globbing and word splitting. [SC2086]
entrypoint.sh:31:37: note: Consider using grep -c instead of grep|wc -l. [SC2126]