update version and Checklist

Checklist

 Before release:
 
-1. Check appropriate issues are fixed
+1. Check milestone is complete
 
-    https://github.com/haskell/time/pulls
-    https://github.com/haskell/time/issues
+    https://github.com/haskell/time/milestones
 
 2. Update version numbers
 

changelog.md

 # Change Log
 
+## [1.8.0.4]
+- Fix "show minBound" bug
+
 ## [1.8.0.3]
 - Add "Quick start" documentation
 

configure.ac

-AC_INIT([Haskell time package], [1.8.0.3], [ashley@semantic.org], [time])
+AC_INIT([Haskell time package], [1.8.0.4], [ashley@semantic.org], [time])
 
 # Safety check: Ensure that we are in the correct source directory.
 AC_CONFIG_SRCDIR([lib/include/HsTime.h])

time.cabal

 name:           time
-version:        1.8.0.3
+version:        1.8.0.4
 stability:      stable
 license:        BSD3
 license-file:   LICENSE