Revert "Try to remove circleci cache to see if that solves the build issue"

This reverts commit f19fc935918721a29fe149fec8abfb78866b262f.

.circleci/config.yml

@@ -100,19 +100,16 @@ jobs:
       - image: circleci/node:8.12
     steps:
       - checkout
-    #   - restore_cache:
-    #       key: dependency-cache-{{ checksum "yarn.lock" }}
-      - run:
-          name: node version
-          command: 'node --version'
+      - restore_cache:
+          key: dependency-cache-{{ checksum "yarn.lock" }}
       - run:
           name: yarn install
           command: 'yarn install --pure-lockfile --no-progress'
           no_output_timeout: 15m
-    #   - save_cache:
-    #       key: dependency-cache-{{ checksum "yarn.lock" }}
-    #       paths:
-    #         - node_modules
+      - save_cache:
+          key: dependency-cache-{{ checksum "yarn.lock" }}
+          paths:
+            - node_modules
       - run:
           name: frontend tests
           command: './scripts/circle-test-frontend.sh'