add maintainers to .cabal

Author: emilypi

zlib.cabal

@@ -6,7 +6,7 @@ copyright:       (c) 2006-2016 Duncan Coutts
 license:         BSD3
 license-file:    LICENSE
 author:          Duncan Coutts <[email protected]>
-maintainer:      Duncan Coutts <[email protected]>
+maintainer:      Duncan Coutts <[email protected]>, Andrew Lelechenko <[email protected]>, Emily Pillmore <[email protected]>, Herbert Valerio Riedel <[email protected]>
 bug-reports:     https://github.com/haskell/zlib/issues
 category:        Codec
 synopsis:        Compression and decompression in the gzip and zlib formats