add a command for showing what directly requires a given package

commands/requires.js

@@ -0,0 +1,23 @@
+import getLockfile from "../functions/get-lockfile"
+import findDependents from "../functions/recursors/find-dependents"
+
+export let command = "requires <name>"
+export let describe = "see what packages directly need a given package"
+export let aliases = [
+	"who-needs",
+	"whoneeds"
+]
+export let builder = yargs =>
+	yargs
+		.positional("name", {
+			describe: "the package name",
+			required: true
+		})
+
+export async function handler (argv) {
+	let lockfile = await getLockfile(argv)
+
+	let requires = await findDependents(argv.name)(lockfile.dependencies)
+
+	console.log(requires.join(" "))
+}