Bump version to 0.7.0.0

changelog.md

 # Changelog for [`hpc` package](http://hackage.haskell.org/package/hpc)
 
+## 0.7.0.0  *TBA*
+
+  * Separate serialised representation from internal representation for
+    processing.
+
+  * Use more efficient internal representation.
+
 ## 0.6.1.0  *October 2019*
 
   * Addition of `readFileUtf8` and `writeFileUtf8` functions.

hpc.cabal

 name:         hpc
-version:      0.6.1.0
+version:      0.7.0.0
 -- NOTE: Don't forget to update ./changelog.md
 license:      BSD3
 license-file: LICENSE