Updated gef-extras.sh installation script

Force script to pip-install the requirements of `gef-extras`

scripts/gef-extras.sh

@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
-
+#
+# Install gef-extras
+# Requires git and pip already installed
+#
 set -e
 
 if [ $# -ge 1 ]; then
@@ -12,6 +15,8 @@ else
 fi
 
 git clone https://github.com/hugsy/gef-extras.git "${DIR}"
+ver=$(gdb -q -nx -ex 'pi print(f"{sys.version_info.major}.{sys.version_info.minor}", end="")' -ex quit)
+python${ver} -m pip install --requirement "${DIR}"/docs/requirements.txt --upgrade
 gdb -q -ex "gef config gef.extra_plugins_dir '${DIR}/scripts'" \
        -ex "gef config pcustom.struct_path '${DIR}/structs'" \
        -ex "gef config syscall-args.path '${DIR}/syscall-tables'" \