Add Travis CI configuration to snappy and fix the make build.

The make build in the open source version uses autoconf, which is set up
to expect a project that follows the gnu standard.

Makefile.am

@@ -24,3 +24,8 @@ nodist_pkgconfig_DATA = snappy.pc
 
 libtool: $(LIBTOOL_DEPS)
 	$(SHELL) ./config.status --recheck
+
+# Needed by autoconf because we use README.md instead of README.
+# See http://stackoverflow.com/q/15013672/
+README: README.md
+	cat $< > $@.tmp