build: bump tslint and stylelint to latest major versions (#18527)

We were one major version behind on tslint and stylelint.

Author: crisbeto

package.json

@@ -99,7 +99,7 @@
     "browser-sync": "^2.26.7",
     "chalk": "^2.4.2",
     "clang-format": "^1.2.4",
-    "codelyzer": "^5.2.0",
+    "codelyzer": "^5.2.1",
     "conventional-changelog": "^3.0.5",
     "dgeni": "^0.4.11",
     "dgeni-packages": "^0.27.1",
@@ -144,12 +144,12 @@
     "semver": "^6.3.0",
     "send": "^0.17.1",
     "shelljs": "^0.8.3",
-    "stylelint": "^12.0.0",
+    "stylelint": "^13.2.0",
     "terser": "^4.3.9",
     "ts-api-guardian": "^0.5.0",
     "ts-node": "^3.0.4",
     "tsickle": "0.38.0",
-    "tslint": "^5.20.0",
+    "tslint": "^6.0.0",
     "tsutils": "^3.0.0",
     "typescript": "~3.7.4",
     "vrsource-tslint-rules": "5.1.1"