fix: Make git submodules use HTTPS instead of SSH link

Author: kelson8

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "test/Unity"]
 	path = test/Unity
-	url = git@github.com:ThrowTheSwitch/Unity.git
+	url = https://github.com/ThrowTheSwitch/Unity.git

CMakeLists.txt

@@ -57,7 +57,7 @@ target_compile_definitions(tmj PUBLIC
 
 # Control symbol visibility
 if(NOT WIN32 AND NOT APPLE)
-    target_link_options(tmj PRIVATE "LINKER:--version-script=src/tmj.sym")
+    target_link_options(tmj PRIVATE "LINKER:--version-script=${CMAKE_CURRENT_SOURCE_DIR}/src/tmj.sym")
 endif()
 
 # Set include directories