Remove SampleRobot (#1658)

SampleRobot provides no benefits over RobotBase to advanced teams and
TimedRobot is recommended for everyone else.

A skeleton template for RobotBase was added.

wpilibcExamples/src/main/cpp/templates/templates.json

@@ -26,6 +26,15 @@
     "foldername": "timedskeleton",
     "gradlebase": "cpp"
   },
+  {
+    "name": "RobotBase Skeleton (Advanced)",
+    "description": "Skeleton (stub) code for RobotBase",
+    "tags": [
+      "RobotBase", "Skeleton"
+    ],
+    "foldername": "robotbaseskeleton",
+    "gradlebase": "cpp"
+  },
   {
     "name": "Command Robot",
     "description": "Command style",
@@ -34,14 +43,5 @@
     ],
     "foldername": "commandbased",
     "gradlebase": "cpp"
-  },
-  {
-    "name": "Sample Robot",
-    "description": "Sample style",
-    "tags": [
-      "Sample"
-    ],
-    "foldername": "sample",
-    "gradlebase": "cpp"
   }
 ]