Add "preexec" from "https://github.com/rcaloras/bash-preexec@0.4.1"

git-vendor-name: preexec
git-vendor-dir: vendor/github.com/rcaloras/bash-preexec
git-vendor-repository: https://github.com/rcaloras/bash-preexec
git-vendor-ref: 0.4.1

vendor/github.com/rcaloras/bash-preexec/test/include-test.bats

@@ -0,0 +1,20 @@
+#!/usr/bin/env bats
+
+@test "should not import if it's already defined" {
+  __bp_imported="defined"
+  source "${BATS_TEST_DIRNAME}/../bash-preexec.sh"
+  [ -z $(type -t __bp_preexec_and_precmd_install) ]
+}
+
+@test "should import if not defined" {
+  unset __bp_imported
+  source "${BATS_TEST_DIRNAME}/../bash-preexec.sh"
+  [ -n $(type -t __bp_install) ]
+}
+
+@test "bp should stop installation if HISTTIMEFORMAT is readonly" {
+  readonly HISTTIMEFORMAT
+  run source "${BATS_TEST_DIRNAME}/../bash-preexec.sh"
+  [ $status -ne 0 ]
+  [[ "$output" =~ "HISTTIMEFORMAT" ]] || return 1
+}