Fixed process_test for systems without bash installed

tests/process_test.cpp

@@ -31,7 +31,7 @@ int main() {
 
   {
     TinyProcessLib::Process process(
-        "bash", "", [output](const char *bytes, size_t n) {
+        "sh", "", [output](const char *bytes, size_t n) {
           *output += std::string(bytes, n);
         },
         nullptr, true);