Move Makefile variable def's to the top.

Looks like there are parts of a Makefile that are parsed from top to
bottom. The last refactoring of the Makefile, which moved the
`IN_DOCKER` logic nearer to the bottom caused the `ifneq` blocks to not
be evaluated in time. The fix was to move this back up to the top which
sadly reduces the Makefile's readability, but at least it's correct
again. Sorry, y'all!

Signed-off-by: Fletcher Nichol <[email protected]>

Pull request: #587
Approved by: juliandunn

Makefile

@@ -1,3 +1,34 @@
+UNAME_S := $(shell uname -s)
+ifeq ($(UNAME_S),Darwin)
+	IN_DOCKER := true
+endif
+
+ifneq ($(IN_DOCKER),)
+	build_args := --build-arg HAB_DEPOT_URL=$(HAB_DEPOT_URL)
+	run_args := -e HAB_DEPOT_URL=$(HAB_DEPOT_URL)
+	run_args := $(run_args) -e HAB_ORIGIN=$(HAB_ORIGIN)
+	ifneq (${http_proxy},)
+		build_args := $(build_args) --build-arg http_proxy="${http_proxy}"
+		run_args := $(run_args) -e http_proxy="${http_proxy}"
+	endif
+	ifneq (${https_proxy},)
+		build_args := $(build_args) --build-arg https_proxy="${https_proxy}"
+		run_args := $(run_args) -e https_proxy="${https_proxy}"
+	endif
+
+	dimage := habitat/devshell
+	docker_cmd := env http_proxy= https_proxy= docker
+	compose_cmd := env http_proxy= https_proxy= docker-compose
+	common_run := $(compose_cmd) run --rm $(run_args)
+	run := $(common_run) shell
+	docs_host := ${DOCKER_HOST}
+	docs_run := $(common_run) -p 9633:9633 shell
+else
+	run :=
+	docs_host := 127.0.0.1
+	docs_run :=
+endif
+
 BIN = director hab sup
 LIB = builder-dbcache builder-protocol common core depot-client depot-core net
 SRV = builder-api builder-jobsrv builder-sessionsrv builder-vault builder-worker depot
@@ -105,37 +136,6 @@ docs: image ## build the docs
 		cp -r images ./components/sup/target/doc/habitat_sup; \
 		echo "<meta http-equiv=refresh content=0;url=habitat_sup/index.html>" > components/sup/target/doc/index.html;'
 
-UNAME_S := $(shell uname -s)
-ifeq ($(UNAME_S),Darwin)
-	IN_DOCKER := true
-endif
-
-ifneq ($(IN_DOCKER),)
-	build_args := --build-arg HAB_DEPOT_URL=$(HAB_DEPOT_URL)
-	run_args := -e HAB_DEPOT_URL=$(HAB_DEPOT_URL)
-	run_args := $(run_args) -e HAB_ORIGIN=$(HAB_ORIGIN)
-	ifneq (${http_proxy},)
-		build_args := $(build_args) --build-arg http_proxy="${http_proxy}"
-		run_args := $(run_args) -e http_proxy="${http_proxy}"
-	endif
-	ifneq (${https_proxy},)
-		build_args := $(build_args) --build-arg https_proxy="${https_proxy}"
-		run_args := $(run_args) -e https_proxy="${https_proxy}"
-	endif
-
-	dimage := habitat/devshell
-	docker_cmd := env http_proxy= https_proxy= docker
-	compose_cmd := env http_proxy= https_proxy= docker-compose
-	common_run := $(compose_cmd) run --rm $(run_args)
-	run := $(common_run) shell
-	docs_host := ${DOCKER_HOST}
-	docs_run := $(common_run) -p 9633:9633 shell
-else
-	run :=
-	docs_host := 127.0.0.1
-	docs_run :=
-endif
-
 define BUILD
 build-$1: image ## builds the $1 component
 	$(run) sh -c 'cd components/$1 && cargo build'