fix(package.json): Bump VTK extension to fix jitter issues in MPR view

package.json

@@ -78,7 +78,7 @@
     "@ohif/extension-dicom-html": "0.0.4",
     "@ohif/extension-dicom-microscopy": "0.0.12",
     "@ohif/extension-dicom-pdf": "0.0.8",
-    "@ohif/extension-vtk": "0.1.5",
+    "@ohif/extension-vtk": "0.1.6",
     "@ohif/i18n": "0.2.3",
     "@tanem/react-nprogress": "^1.1.25",
     "classnames": "^2.2.6",