Support `cpuperiod` and `cpuquota` container limits for build

Docker API v1.19 (see [changelog](https://docs.docker.com/engine/api/version-history/#v119-api-changes) introduced two new arguments to `build`:

> POST /build accepts cpuperiod and cpuquota options

It would be great to update the `container_limits` valid keys in `BuildApiMixin` to introduce them.