Switch installer to rc5 (#828)

Author: droserasprout

src/dipdup/install.py

@@ -164,7 +164,7 @@ def install(
 
     if not any((version, ref, path)):
         # FIXME: Temporary, remove when 7.0.0 is released
-        version = '7.0.0rc4'
+        version = '7.0.0rc5'
 
     env = DipDupEnvironment()
     env.prepare()