Revert "Don't run testrpc for the rest of the tests"

This reverts commit ae8cb2e6a8.

.circleci/config.yml

@@ -46,6 +46,10 @@ jobs:
       - restore_cache:
           keys:
             - repo-{{ .Environment.CIRCLE_SHA1 }}
+      - run:
+          name: testrpc
+          command: npm run testrpc -- --db testrpc_snapshot
+          background: true
       - run: yarn lerna:run --ignore 0x.js test:circleci
   lint:
     working_directory: ~/repo