Add Vim modelines

Change-Id: I23f30cd9be56089498089f8b12abe3f3e186b525
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/sensorcache.hpp b/sensorcache.hpp
index 15a1d7c..02405ff 100644
--- a/sensorcache.hpp
+++ b/sensorcache.hpp
@@ -28,3 +28,5 @@
 };
 
 #endif
+
+// vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4