Change the schedule to allow slip time.

We have to have time to slip release in case of major bugs.

docs/docsite/rst/roadmap/ROADMAP_2_7.rst

@@ -10,13 +10,17 @@ Release Schedule
 Expected
 ========
 
-- 2018-09-06 Core Freeze (Engine and Core Modules/Plugins)
+- 2018-08-23 Core Freeze (Engine and Core Modules/Plugins)
-- 2018-09-06 Alpha Release 1
+- 2018-08-23 Alpha Release 1
-- 2018-09-13 Community Freeze (Non-Core Modules/Plugins)
+- 2018-08-30 Community Freeze (Non-Core Modules/Plugins)
-- 2018-09-13 Beta Release 1
+- 2018-08-30 Beta Release 1
-- 2018-09-27 Release Candidate 1
+- 2018-09-06 Release Candidate 1 (If needed)
+- 2018-09-13 Release Candidate 2 (If needed)
+- 2018-09-20 Release Candidate 3 (If needed)
+- 2018-09-27 Release Candidate 4 (If needed)
 - 2018-10-04 General Availability
 
+
 Cleaning Duty
 -------------