ensure make dev target puts the newly constructed binary onto the PATH (#12318)

This restores the prior behavior of make dev and ensures that tests
using the sdk package (like the api package) will correctly locate the
consul binary under test.

Also ensure the constructed consul binary is present on the path for sdk-based tests.

GNUmakefile

@@ -18,6 +18,8 @@ GOTAGS ?=
 GOPATH=$(shell go env GOPATH)
 MAIN_GOPATH=$(shell go env GOPATH | cut -d: -f1)
 
+export PATH := $(PWD)/bin:$(PATH)
+
 ASSETFS_PATH?=agent/uiserver/bindata_assetfs.go
 # Get the git commit
 GIT_COMMIT?=$(shell git rev-parse --short HEAD)
@@ -145,7 +147,8 @@ dev: dev-build
 
 dev-build:
 	mkdir -p bin
-	CGO_ENABLED=0 go build -o ./bin -ldflags "$(GOLDFLAGS)" -tags "$(GOTAGS)"
+	CGO_ENABLED=0 go install -ldflags "$(GOLDFLAGS)" -tags "$(GOTAGS)"
+	cp -f ${MAIN_GOPATH}/bin/consul ./bin/consul
 
 dev-docker: linux
 	@echo "Pulling consul container image - $(CONSUL_IMAGE_VERSION)"