Land rapid7#6735, bump rvm ruby version to 2.1.9

Brent Cook · Brent Cook · commit 39bd501b737f · 2016-04-01T20:05:44.000-05:00
diff --git a/.ruby-version b/.ruby-version
@@ -1 +1 @@
-2.1.8
+2.1.9
diff --git a/.travis.yml b/.travis.yml
@@ -45,4 +45,4 @@ git:
 branches:
   except:
     - gh-pages
-    - metakitty
+    - metakitty
