add circleci with test coverage

Signed-off-by: Adolfo García Veytia (Puerco) <adolfo.garcia@uservers.net>

throttler/.circleci/config.yml

@@ -0,0 +1,20 @@
+# Golang CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/language-go/ for more details
+version: 2
+jobs:
+  build:
+    docker:
+      # specify the version
+      - image: golang
+
+    #### TEMPLATE_NOTE: go expects specific checkout path representing url
+    #### expecting it in the form of
+    ####   /go/src/github.com/circleci/go-tool
+    ####   /go/src/bitbucket.org/circleci/go-tool
+    working_directory: /go/src/github.com/nozzle/throttler
+    steps:
+      - checkout
+
+      # specify any bash command here prefixed with `run: `
+      - run: go test -coverprofile=coverage.txt -covermode=atomic