Assure `lua_modules` directory tree (test deps.) is not part of source or binary release.

[mrutkows]

API Gateway installs several Lua modules (via luarocks package installer) that are copied as part of the Travis build scipts (see https://github.com/apache/incubator-openwhisk-apigateway/blob/master/tests/install-deps.sh).

including:

# Install test dependencies
mkdir -p lua_modules
luarocks install --tree=lua_modules lua-cjson
luarocks install --tree=lua_modules luabitop
luarocks install --tree=lua_modules luasocket
luarocks install --tree=lua_modules sha1
luarocks install --tree=lua_modules md5
luarocks install --tree=lua_modules net-url
luarocks install --tree=lua_modules luafilesystem

None should be part of any Apache release archive/package.

[mrutkows]

@houshengbo we need to validate the removal with Dragos or Matt Hamann before we submit a vote to release. In addition, I should note that the install script that installs these modules also installs these modules:

# Install global dependencies
luarocks install busted
luarocks install luacov

which should be referenced in the LICENSE and not deleted from TAR file.

[houshengbo]

@mrutkows Tests folder is excluded, since there will not be any lua_modules module to be released.