set alpine version to 3.11.3

Author: dylanhitt

.travis.yml

@@ -73,7 +73,7 @@ jobs:
 
   - name: Integration test
     script:
-      - docker pull docker.io/library/alpine:3.11
+      - docker pull docker.io/library/alpine:3.11.3
       - make integration-linux
 
   - stage: deploy

README.md

@@ -725,7 +725,7 @@ The `docker` node type executes the given command inside a docker container.
 nodes:
   docker-host:
     type: docker
-    image: docker.io/library/alpine:3.11
+    image: docker.io/library/alpine:3.11.3
     user: 1000 # define the owner of the executed command
 config:
   nodes:

go.mod

@@ -23,3 +23,5 @@ require (
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/yaml.v2 v2.2.4
 )
+
+go 1.13

integration/linux/docker.yaml

@@ -1,7 +1,7 @@
 nodes:
   docker-host:
     type: docker
-    image: docker.io/library/alpine:3.11
+    image: docker.io/library/alpine:3.11.3
     user: 1001
 
 config: