Fix LGTM errors.

lgtm.yml

@@ -3,3 +3,6 @@ path_classifiers:
     - libs/*.js
     - libs/loaders/*.js
     - libs/three_loaders/*.js
+  test:
+    - test
+    - sandbox

tools/update_engine_exports.py

@@ -1,6 +1,5 @@
 import os
 import sys
-import json
 import re
 
 from lib import tools_lib as Tools

tools/update_libs.py

@@ -1,7 +1,6 @@
 import os
 import sys
 import shutil
-import json
 
 pickrFileMap = [
     [os.path.join ('@simonwep', 'pickr', 'LICENSE'), os.path.join ('pickr.license.md')],
@@ -68,10 +67,6 @@ def Main (argv):
     nodeModulesDir = os.path.join (rootDir, 'node_modules')
     libsDir = os.path.join (rootDir, 'libs')
 
-    package = None
-    with open (os.path.join (rootDir, 'package.json')) as packageJson:
-        package = json.load (packageJson)
-
     UpdateModule (pickrFileMap, nodeModulesDir, libsDir)
     UpdateModule (threeJsFileMap, nodeModulesDir, libsDir)
     UpdateModule (dracoFileMap, nodeModulesDir, libsDir)