Check docker credentials in docker:login (#40)

* Update `LICENSE`

* Update TravisCI `Go` version

* Check `Docker` credentials in `docker:login`

* Remove comments. Add `else` condition

Author: aknysh

.README.md

@@ -49,6 +49,7 @@ Here's how to get started...
 |
 {{- (datasource "contributor").erik }} |
 {{- (datasource "contributor").igor }} |
-|---|---|
+{{- (datasource "contributor").andriy }} |
+|---|---|---|
 
 {{ (datasource "contributor")._links }}

.gitignore

@@ -1 +1,3 @@
-./terraform
+./terraform
+.idea
+build-harness.iml

.travis.yml

@@ -1,7 +1,7 @@
 sudo: required
 language: go
 go:
-  - 1.7.x
+  - 1.9.x
 addons:
   apt:
     packages:

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright {yyyy} {name of copyright owner}
+   Copyright 2017-2018 Cloud Posse, LLC
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

modules/docker/Makefile.hub

@@ -2,7 +2,8 @@
 ## Use DOCKER_HUB_USERNAME and DOCKER_HUB_PASSWORD env variables to pass credentials
 ## Login into docker hub
 docker\:login: $(DOCKER)
-	$(call assert-set,DOCKER)
-	$(call assert-set,DOCKER_HUB_USERNAME)
-	$(call assert-set,DOCKER_HUB_PASSWORD)
-	@$(DOCKER) login --username="$(DOCKER_HUB_USERNAME)" --password="$(DOCKER_HUB_PASSWORD)"
+	@if [ -n "$DOCKER" ] && [ -n "$DOCKER_HUB_USERNAME" ] && [ -n "$DOCKER_HUB_PASSWORD" ]; then\
+      @$(DOCKER) login --username="$(DOCKER_HUB_USERNAME)" --password="$(DOCKER_HUB_PASSWORD)";\
+	else \
+	  echo "Skipping docker:login. Docker credentials (DOCKER_HUB_USERNAME or DOCKER_HUB_PASSWORD) are not set"; \
+	fi;