Add Continuous Integration Tests (#9)

.gitignore

@@ -2,9 +2,9 @@
 *.tfstate
 *.tfstate.backup
 
-# Module directory
 .terraform
 .idea
 *.iml
 
-.gitignore
+.build-harness
+build-harness

.travis.yml

@@ -0,0 +1,16 @@
+addons:
+  apt:
+    packages:
+      - git
+      - make
+      - curl
+
+install:
+  - make init
+
+script:
+  - make terraform:install
+  - make terraform:get-plugins
+  - make terraform:get-modules
+  - make terraform:lint
+  - make terraform:validate

Makefile

@@ -0,0 +1,6 @@
+SHELL := /bin/bash
+
+-include $(shell curl -sSL -o .build-harness "https://git.io/build-harness"; echo .build-harness)
+
+lint:
+	$(SELF) terraform:install terraform:get-modules terraform:get-plugins terraform:lint terraform:validate

README.md

@@ -1,4 +1,4 @@
-# terraform-null-label
+# terraform-null-label [![Build Status](https://travis-ci.org/cloudposse/terraform-null-label.svg)](https://travis-ci.org/cloudposse/terraform-null-label)
 
 Terraform module designed to generate consistent label names and tags for resources. Use `terraform-null-label` to implement a strict naming convention. 
 
@@ -12,7 +12,6 @@ All [Cloud Posse modules](https://github.com/cloudposse?utf8=%E2%9C%93&q=tf_&typ
 
 -**NOTE:** The `null` refers to the primary Terraform [provider](https://www.terraform.io/docs/providers/null/index.html) used in this module.
 
-
 ## Usage
 
 ### Simple Example