[perf] use docker layer caching from previous build

server-ce/Makefile

@@ -2,9 +2,11 @@
 
 SHARELATEX_BASE_TAG := sharelatex/sharelatex-base
 SHARELATEX_TAG := sharelatex/sharelatex
+SHARELATEX_BASE_CACHE := $(shell echo $(SHARELATEX_BASE_TAG) | sed -E 's/(.+):.+/\1:latest/')
 
 build-base:
-	docker build -f Dockerfile-base -t  $(SHARELATEX_BASE_TAG) .
+	docker pull $(SHARELATEX_BASE_CACHE)
+	docker build -f Dockerfile-base --pull --cache-from $(SHARELATEX_BASE_CACHE) -t $(SHARELATEX_BASE_TAG) .
 
 
 build-community: