[Tests] up to node v7.9

Author: ljharb

.travis.yml

@@ -2,7 +2,7 @@ language: node_js
 os:
  - linux
 node_js:
-  - "7.7"
+  - "7.9"
   - "6.10"
   - "5.12"
   - "4.8"
@@ -31,6 +31,10 @@ matrix:
   include:
     - node_js: "node"
       env: PRETEST=true
+    - node_js: "7.8"
+      env: TEST=true ALLOW_FAILURE=true
+    - node_js: "7.7"
+      env: TEST=true ALLOW_FAILURE=true
     - node_js: "7.6"
       env: TEST=true ALLOW_FAILURE=true
     - node_js: "7.5"