leverage makefile to run build tasks (#976)

remove circle ci

cobra/Makefile

@@ -0,0 +1,23 @@
+XC_OS="linux darwin"
+XC_ARCH="amd64"
+XC_PARALLEL="2"
+BIN="../bin"
+SRC=$(shell find . -name "*.go")
+
+ifeq (, $(shell which gox))
+$(warning "could not find gox in $(PATH), run: go get github.com/mitchellh/gox")
+endif
+
+.PHONY: all build
+
+default: all
+
+all: build
+
+build:
+	gox \
+		-os=$(XC_OS) \
+		-arch=$(XC_ARCH) \
+		-parallel=$(XC_PARALLEL) \
+		-output=$(BIN)/{{.Dir}}_{{.OS}}_{{.Arch}} \
+		;