Bump 'future' release in e2e_conf.yaml for 0.7

Author: mdbooth

test/e2e/data/e2e_conf.yaml

@@ -89,7 +89,7 @@ providers:
       new: "--v=4"
     - old: "--leader-elect"
       new: "--leader-elect=false\n        - --sync-period=1m"
-  - name: v0.6.99
+  - name: v0.7.99
     value: ../../../config/default
     # This is the upcoming version.
     # Specify no contract so that upgrade tests that start from a specific contract won't pick it up.