Add Go 1.12 to Travis CI (#538)

Also update to the latest version of Makefile.common.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

.travis.yml

@@ -1,5 +1,3 @@
-# sudo is enabled because it provides more memory which was needed to run go test -race
-sudo: required
 dist: trusty
 language: go
 os:
@@ -10,6 +8,7 @@ os:
 go:
   - 1.10.x
   - 1.11.x
+  - 1.12.x
 
 go_import_path: github.com/prometheus/tsdb
 

Makefile.common

@@ -70,7 +70,7 @@ else
 	GO_BUILD_PLATFORM ?= $(GOHOSTOS)-$(GOHOSTARCH)
 endif
 
-PROMU_VERSION ?= 0.2.0
+PROMU_VERSION ?= 0.3.0
 PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_VERSION)/promu-$(PROMU_VERSION).$(GO_BUILD_PLATFORM).tar.gz
 STATICCHECK_VERSION ?= 2019.1
 STATICCHECK_URL     := https://github.com/dominikh/go-tools/releases/download/$(STATICCHECK_VERSION)/staticcheck_$(GOHOSTOS)_$(GOHOSTARCH)