fix(svg-to-ts): pins svg-to-ts to a specific safe version

An issue was encountered while updating to the latest version of svg-to-ts, this commit pins it to a
specific version. An [issue](nivekcode/svg-to-ts#91) is raised against the
svg-to-ts repo, depending on the outcome we can either workaround it locally or help provide a fix.

Author: andy-polhill

package-lock.json

@@ -114,7 +114,7 @@
     "stylelint": "^11.1.1",
     "stylelint-config-recommended": "^3.0.0",
     "stylelint-selector-bem-pattern": "^2.1.0",
-    "svg-to-ts": "^5.7.1",
+    "svg-to-ts": "5.0.1",
     "svgo": "^1.3.2",
     "ts-mockito": "^2.6.1",
     "ts-node": "^9.0.0",