b27fabe fix(@angular-devkit/build-angular): remove deprecated istanbul from dependencies (#13567)

Author: Angular Builds

package.json

@@ -6,12 +6,12 @@
   "typings": "src/index.d.ts",
   "builders": "builders.json",
   "dependencies": {
-    "@angular-devkit/architect": "github:angular/angular-devkit-architect-builds#e6f96fb",
-    "@angular-devkit/build-optimizer": "github:angular/angular-devkit-build-optimizer-builds#e6f96fb",
-    "@angular-devkit/build-webpack": "github:angular/angular-devkit-build-webpack-builds#e6f96fb",
-    "@angular-devkit/core": "github:angular/angular-devkit-core-builds#e6f96fb",
-    "@ngtools/webpack": "github:angular/ngtools-webpack-builds#e6f96fb",
-    "ajv": "6.8.1",
+    "@angular-devkit/architect": "github:angular/angular-devkit-architect-builds#b27fabe",
+    "@angular-devkit/build-optimizer": "github:angular/angular-devkit-build-optimizer-builds#b27fabe",
+    "@angular-devkit/build-webpack": "github:angular/angular-devkit-build-webpack-builds#b27fabe",
+    "@angular-devkit/core": "github:angular/angular-devkit-core-builds#b27fabe",
+    "@ngtools/webpack": "github:angular/ngtools-webpack-builds#b27fabe",
+    "ajv": "6.7.0",
     "autoprefixer": "9.4.7",
     "circular-dependency-plugin": "5.0.2",
     "clean-css": "4.2.1",