Update release Id to 1.0.0-beta

Update the release version for the release.

Change-Id: I91b4593b090bf605f3cc0c54fa3324dfd9363bb9
Signed-off-by: Gyorgy Szing <Gyorgy.Szing@arm.com>
diff --git a/version.txt b/version.txt
index 6c6aa7c..537aabf 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-0.1.0
\ No newline at end of file
+1.0.0-beta
\ No newline at end of file