Remove circle ci implementation due to Golang bug.

I've tried to set-up circleci but I came across a Golang issue that was
preventing CPU tests to PASS. Instead of ignoring those tests I've
submitted an issue to Go (https://github.com/golang/go/issues/11609)
hoping that this gets fixed soon.

circle.yml

@@ -1,3 +0,0 @@
-test:
-  override:
-      - go test -short ./...