build: update to use go1.12 for the build

.travis.yml

@@ -8,7 +8,7 @@ go:
 - 1.9.x
 - 1.10.x
 - 1.11.x
-- 1.12rc1
+- 1.12.x
 - tip
 go_import_path: github.com/ncw/rclone
 before_install:
@@ -44,7 +44,7 @@ matrix:
   - go: tip
   include:
   - os: osx
-    go: 1.12rc1
+    go: 1.12.x
     env: GOTAGS=""
     cache:
       directories:
@@ -56,5 +56,5 @@ deploy:
   on:
     repo: ncw/rclone
     all_branches: true
-    go: 1.12rc1
+    go: 1.12.x
     condition: $TRAVIS_PULL_REQUEST == false

Makefile

@@ -17,8 +17,8 @@ ifneq ($(TAG),$(LAST_TAG))
 endif
 GO_VERSION := $(shell go version)
 GO_FILES := $(shell go list ./... | grep -v /vendor/ )
-# Run full tests if go >= go1.11
-FULL_TESTS := $(shell go version | perl -lne 'print "go$$1.$$2" if /go(\d+)\.(\d+)/ && ($$1 > 1 || $$2 >= 11)')
+# Run full tests if go >= go1.12
+FULL_TESTS := $(shell go version | perl -lne 'print "go$$1.$$2" if /go(\d+)\.(\d+)/ && ($$1 > 1 || $$2 >= 12)')
 BETA_PATH := $(BRANCH_PATH)$(TAG)
 BETA_URL := https://beta.rclone.org/$(BETA_PATH)/
 BETA_UPLOAD_ROOT := memstore:beta-rclone-org