REL : Release version 6.0.0 of envisage (#413)

update the version information accordingly and flip the IS_RELEASED
flag. once this commit is merged into the 6.0 maintenance branch, the
merged commit will be tagged as a release

	modified:   setup.py

setup.py

@@ -18,11 +18,11 @@
 # release. The actual package version is autogenerated from this information
 # together with information from the version control system, and then injected
 # into the package source.
-MAJOR = 5
-MINOR = 1
+MAJOR = 6
+MINOR = 0
 MICRO = 0
 PRERELEASE = ""
-IS_RELEASED = False
+IS_RELEASED = True
 
 # If this file is part of a Git export (for example created with "git archive",
 # or downloaded from GitHub), ARCHIVE_COMMIT_HASH gives the full hash of the