fix plugin installation and updation

previously - always the latest version of the plugin
was being installed. this fixes that, by only installing
the version mentioned in the plugin.yaml

plugin.yaml

@@ -4,5 +4,5 @@ usage: "generate json schema for values yaml"
 description: "generate json schema for values yaml"
 command: "$HELM_PLUGIN_DIR/bin/helm-schema-gen"
 hooks:
-  install: "cd $HELM_PLUGIN_DIR; scripts/install.sh"
-  update: "cd $HELM_PLUGIN_DIR; scripts/install.sh"
+  install: "cd $HELM_PLUGIN_DIR; scripts/install_version.sh"
+  update: "cd $HELM_PLUGIN_DIR; scripts/install_version.sh"

scripts/install_version.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+## this script must be called ONLY
+## from the root of this project
+
+## this script installs a the
+## version of the plugin mentioned
+## in the plugin.yaml
+
+version="$(cat plugin.yaml | grep "version" | cut -d '"' -f 2)"
+./scripts/install.sh $version