Add bin/* to shellcheck check (#603)

* Add shellcheck to rest of bin/* scripts

bin/detect

@@ -17,7 +17,7 @@ error() {
 	exit 1
 }
 
-if [ -f $1/package.json ]; then
+if [ -f "$1/package.json" ]; then
   echo 'Node.js'
   exit 0
 fi
@@ -59,7 +59,7 @@ If you are trying to deploy a Node.js application, ensure that this
 file is present at the top level directory. This directory has the
 following files:
 
-$(ls -1p $1)
+$(ls -1p "$1")
     
 If you are trying to deploy an application written in another
 language, you need to change the list of buildpacks set on your

bin/test-compile

 #!/usr/bin/env bash
 
-BP_DIR=$(cd "$(dirname ${0:-})"; cd ..; pwd)
+BP_DIR=$(cd "$(dirname "${0:-}")" || exit; cd ..; pwd)
 
-source $BP_DIR/lib/environment.sh
+# shellcheck source=lib/environment.sh
+source "$BP_DIR/lib/environment.sh"
 
 export NPM_CONFIG_PRODUCTION=${NPM_CONFIG_PRODUCTION:-false}
 export NODE_ENV=${NODE_ENV:-test}

makefile

 test: heroku-18 heroku-16 cedar-14
 
 shellcheck:
-	@shellcheck -x bin/compile 
-	@echo TODO shellcheck bin/detect bin/release bin/test bin/test-compile
+	@shellcheck -x bin/compile bin/detect bin/release bin/test bin/test-compile
 	@echo TODO shellcheck -x lib/**/*.sh 
 	@echo TODO shellcheck -x ci-profile/**/*.sh
 	@echo TODO shellcheck -x etc/**/*.sh