build: also provide lzip compressed tarballs

Suggested by Matias Fonzo <selk@dragora.org>.

* cfg.mk: Post announcements to bison-announce.
* configure.ac: Build lzip packages.
* .travis.yml: Build only xz, we don't care about the other formats
here.

.travis.yml

@@ -46,7 +46,7 @@ jobs:
         - ./bootstrap
         - ./configure --enable-gcc-warnings || { cat config.log && false; }
         - make -j2
-        - make -j2 dist
+        - make -j2 dist-xz
         # Can help understanding why we get "dirty" tarballs.
         - git status
         - dist=$(echo bison*.xz)

cfg.mk

@@ -51,7 +51,7 @@ gnulib_dir = $(srcdir)/gnulib
 bootstrap-tools = autoconf,automake,flex,gettext,gnulib
 
 announcement_Cc_ = \
-  bug-bison@gnu.org, help-bison@gnu.org, bison-patches@gnu.org, \
+  bug-bison@gnu.org, bison-announce@gnu.org, \
   coordinator@translationproject.org
 
 update-copyright: update-b4-copyright update-package-copyright-year

configure.ac

@@ -36,10 +36,8 @@ AC_DEFINE_UNQUOTED([PACKAGE_COPYRIGHT_YEAR], [$PACKAGE_COPYRIGHT_YEAR],
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])
 
-# We use Automake 1.14's %D% and %C%.
-#
 # When we move to Automake 1.16, simplify examples/c/reccalc/local.mk.
-# Our CI runs on Xenial, which has only Automake 1.15.
+# Our CI build the packages on Bionic, which has only Automake 1.15.
 #
 # We want gnits strictness only when rolling a stable release.  For
 # release candidates, we use version strings like 2.4.3_rc1, but gnits
@@ -47,7 +45,7 @@ AC_CONFIG_MACRO_DIR([m4])
 # releases, we want to be able run make dist without being required to
 # add a bogus NEWS entry.  In that case, the version string
 # automatically contains a dash, which we also let disable gnits.
-AM_INIT_AUTOMAKE([1.14 dist-xz nostdinc
+AM_INIT_AUTOMAKE([1.15 dist-lzip dist-xz nostdinc
                  color-tests parallel-tests
                  silent-rules]
                  m4_bmatch(m4_defn([AC_PACKAGE_VERSION]), [[-_]],