bin: replace double backticks (``) with $()

This has been the recommended way of launching subshells for ages, and is easier
to type and on the eye.

For a quick reference, see:
https://unix.stackexchange.com/questions/5778/whats-the-difference-between-stuff-and-stuff#5782

bin/buildForWindows.sh

@@ -3,7 +3,7 @@
 NODE_VERSION="10.18.0"
 
 #Move to the folder where ep-lite is installed
-cd `dirname $0`
+cd $(dirname $0)
 
 #Was this script started in the bin folder? if yes move out
 if [ -d "../bin" ]; then