Fix detection of Nexus devices

fixes #233

test/acceptance/useragentstrings.yml

@@ -254,7 +254,21 @@
           type: "tablet"
         engine: 
           name: "Blink"
-  Amazon Silk: 
+    -
+      ua: "Mozilla/5.0 (Linux; Android 7.0; Nexus 6P Build/NRD90T) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.111 Mobile Safari/537.36"
+      spec:
+        browser:
+          name: "Chrome"
+          version: "63.0.3239.111"
+        os:
+          name: "Android"
+          version: "7.0"
+        platform:
+          type: "mobile"
+          vendor: "Nexus"
+        engine:
+          name: "Blink"
+  Amazon Silk:
     - 
       ua: "Mozilla/5.0 (Linux; U; Android 4.0.3; en-us; KFTT Build/IML74K) AppleWebKit/535.19 (KHTML, like Gecko) Silk/3.4 Mobile Safari/535.19 Silk-Accelerated=true"
       spec: 
@@ -607,7 +621,7 @@
           name: "Android"
           version: "5.1.1"
         platform: 
-          type: "tablet"
+          type: "mobile"
           vendor: "Nexus"
         engine: 
           name: "Blink"