Use cmake module instead of shared for nvim-test

On a Mac using shared creates libnvim-test.dylib which cannot be found
by the hardcoded .so extension in helpers.moon, causing the unittests to
fail. However, using module creates libnvim-test.so, allowing the tests
to run. There will still be problems running the tests on windows,
because both shared and module create dll file which will not be found
by in helpers.moon.

.gitignore

@@ -8,6 +8,8 @@ build/
 *.swp
 *~
 *.pyc
+*.o
+*.so
 src/po/vim.pot
 
 src/po/*.ck

src/CMakeLists.txt

@@ -13,7 +13,7 @@ list(APPEND NEOVIM_SOURCES "${PROJECT_BINARY_DIR}/config/auto/pathdef.c")
 file( GLOB OS_SOURCES os/*.c )
 
 add_executable (nvim ${NEOVIM_SOURCES} ${OS_SOURCES})
-add_library (nvim-test SHARED ${NEOVIM_SOURCES} ${OS_SOURCES}) 
+add_library (nvim-test MODULE ${NEOVIM_SOURCES} ${OS_SOURCES})
 
 # The libraries we link against for nvim
 set(NVIM_LINK_LIBRARIES m ${LibUV_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})