improve travis-ci

.travis.yml

@@ -16,7 +16,7 @@ install:
       brew install mingw-w64;
     else
       wget -q https://dl.google.com/android/repository/android-ndk-r19c-linux-x86_64.zip;
-      unzip -q ./android-ndk-r19c-linux-x86_64.zip;
+      unzip -q -o ./android-ndk-r19c-linux-x86_64.zip;
     fi
 
 script:

packages/z/zlib/xmake.lua

@@ -12,7 +12,7 @@ package("zlib")
     on_install("linux", "macosx", function (package)
         import("package.tools.autoconf").install(package, {"--static"})
     end)
-
+ 
     on_install("windows", function (package)
         io.gsub("win32/Makefile.msc", "%-MD", "-" .. package:config("vs_runtime"))
         os.vrun("nmake -f win32\\Makefile.msc zlib.lib")