simplify the prepare_deps script

prepare_deps.sh

 #!/bin/bash
 
-npm install
-
-echo '*** Asking for sudo to install browserify globally ***'
-sudo npm install -g browserify
-
-echo '*** Fetching and updating required submodules ***'
-git submodule init
-git submodule update
-
-cd lib/jwcrypto
-./bundle.sh
-
 echo ''
 echo '*** Generating keys and placing them into correct location ***'
+cd lib/jwcrypto
 node generate-keypair.js
 
 mv key.publickey ../../var/root.publickey
 mv key.secretkey ../../var/root.secretkey
 cd ../..
-