Add issue template

ISSUE_TEMPLATE.md

@@ -0,0 +1,26 @@
+### New Issue Checklist
+
+- [ ] I have looked at the [Documentation](http://snapkit.io/docs)
+- [ ] I have read the [F.A.Q.](http://snapkit.io/faq)
+
+### Environment / Configuration
+
+##### Platform
+
+* [ ] OS X
+* [ ] iOS
+
+##### Versions
+
+* Platform version is: `INSERT PLATFORM VERSION`
+* SnapKit version is: `INSERT SNAPKIT VERSION`
+
+##### Integration
+
+- [ ] Carthage
+- [ ] Cocoapods
+- [ ] Manually / Other
+
+### Issue
+
+`INSERT ISSUE DESCRIPTION`