Add docker registry login

Author: guilhem

.github/main.workflow

@@ -2,8 +2,8 @@ workflow "Deploy" {
   on = "push"
   resolves = [
     "goreleaser",
-    "is-tag",
     "Test on Travis CI",
+    "Docker Registry",
   ]
 }
 
@@ -12,16 +12,24 @@ action "is-tag" {
   args = "tag"
 }
 
+
+
+action "Test on Travis CI" {
+  uses = "travis-ci/actions@master"
+  secrets = ["TRAVIS_TOKEN"]
+}
+
+action "Docker Registry" {
+  uses = "actions/docker/login@8cdf801b322af5f369e00d85e9cf3a7122f49108"
+  needs = ["is-tag"]
+  secrets = ["DOCKER_USERNAME", "DOCKER_PASSWORD"]
+}
+
 action "goreleaser" {
   uses = "docker://goreleaser/goreleaser"
   secrets = [
     "GORELEASER_GITHUB_TOKEN",
   ]
   args = "release"
-  needs = ["is-tag","Test on Travis CI"]
-}
-
-action "Test on Travis CI" {
-  uses = "travis-ci/actions@master"
-  secrets = ["TRAVIS_TOKEN"]
+  needs = ["is-tag", "Test on Travis CI", "Docker Registry"]
 }