Check shell scripts with shellcheck

[efirs]

Add shellcheck build target which would run shellcheck scripts/*.sh.
Make test target dependent on shellcheck to run it along with other tests.

[praveen0288]

#!/bin/bash
#This Script is for if-then

echo What is yor rate of intrest?
echo
read A
count=0
num=20
echo
if{$A -lt $num}
then
echo 'YOU ARE GOOD'
else
echo 'YOU ARE BAD'
fi