Drop support for 0.10/0.12

nyc uses `const` and code coverage is _definitely_ worth it.

Author: strugee

.travis.yml

@@ -1,7 +1,5 @@
 language: node_js
 node_js:
-  - "0.10"
-  - "0.12"
   - "4"
   - "6"
 env:

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 `smart-spawn` follows [Semantic Versioning][1].
 
+## 3.0.0 - Future
+
+### Breaking
+
+* Node 0.10/0.12 are no longer supported
+
 ## 2.0.1 - 2016-11-09
 
 ### Fixed

README.md

@@ -13,6 +13,8 @@ Spawn an async process and get back stdout, handling errors
 
 ## Usage
 
+You need Node 4+. It'll probably run on 0.10 and 0.12 too, but the test suite doesn't cover those versions, so you're on your own.
+
 ```js
 var smartSpawn = require('smart-spawn');