refactor(api): move CLI-specific API contract into this repo, add openapi as submodule (#95)

.circleci/config.yml

@@ -26,6 +26,9 @@ jobs:
     working_directory: /home/circleci/go/src/github.com/influxdata/influx-cli
     steps:
       - checkout
+      - run:
+          name: Init openapi submodule
+          command: git submodule update --init --recursive
       - run:
           name: Upgrade Go
           command: |