update document to r0.8

Author: miyosuda

README.md

@@ -71,4 +71,4 @@ and copy .so file into app/src/main/jniLibs/armeabi-v7a/ with
 (Unlike original Android demo in Tensorflow, you don't need to install bazel to build this demo.
 And it seems that original Tensorflow Android demo fails to be built with bazel and latest ndk-r11b, and requires old ndk-r10e now, but this demo can be built with r11b.)
 
-Tensorflow library files (.a files) and header files are extracted from original Tensorflow Android demo r0.7.
+Tensorflow library files (.a files) and header files are extracted from original Tensorflow Android demo r0.8.