rename write,read to writeMeta,readMeta

The blobs::DataInterface specifies two methods, write and read which are
meant to be implemented to write or read configuration for the data
interface implementation.

Change-Id: I831a8611596fca50570a4156cbdcfa5c810c0315
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/data_handler.hpp b/data_handler.hpp
index 1bee432..75f7660 100644
--- a/data_handler.hpp
+++ b/data_handler.hpp
@@ -43,7 +43,7 @@
      * @param[in] configuration - byte vector of data.
      * @return bool - returns true on success.
      */
-    virtual bool write(const std::vector<std::uint8_t>& configuration) = 0;
+    virtual bool writeMeta(const std::vector<std::uint8_t>& configuration) = 0;
 
     /**
      * read configuration.
@@ -51,7 +51,7 @@
      * @return bytes - whatever bytes are required configuration information for
      * the mechanism.
      */
-    virtual std::vector<std::uint8_t> read() = 0;
+    virtual std::vector<std::uint8_t> readMeta() = 0;
 };
 
 struct DataHandlerPack