bump min go version to 1.13 for trimpath

.travis.yml

@@ -3,7 +3,7 @@ language: go
 dist: xenial
 
 go:
-  - "1.12"
+  - "1.13"
   - "master"
 
 os:
@@ -39,11 +39,11 @@ jobs:
       script: go mod download -json
     - stage: test
       name: end-to-end
-      go: "1.12"
+      go: "1.13"
       script: make e2e
     - stage: release
       script: make release GOARCHES="amd64 arm arm64"
-      go: "1.12.7" # explicit version to ease reproducibility
+      go: "1.13.1" # explicit version to ease reproducibility
       if: tag IS present
       deploy:
         provider: releases

Makefile

@@ -1,6 +1,6 @@
 VERSION := $(shell git describe --tags --dirty --always)
 
-GOFLAGS := -ldflags "-X main.version=$(VERSION)" -gcflags=all=-trimpath=$(PWD) -asmflags=all=-trimpath=$(PWD)
+GOFLAGS := -ldflags "-X main.version=$(VERSION)" -trimpath
 
 GOARCHES := $(shell go env GOARCH)
 

tests/Dockerfile

@@ -1,5 +1,5 @@
 # stick to non-alpine so we can reuse build from travis host (avoid libc compat issues)
-FROM golang:1.12
+FROM golang:1.13
 
 ARG DEBIAN_FRONTEND=noninteractive