make header tests work

Author: smehringer

include/bio/format/sam_input_handler.hpp

@@ -221,7 +221,14 @@ class format_input_handler<sam> : public format_input_handler_base<format_input_
             header_string += file_it->line;
             header_string += "\n";
         }
-        header = map_io::header<std::vector<std::string>>{std::move(header_string)};
+
+        if (header_string.ends_with("\r\n"))
+            header_string = header_string.substr(0, header_string.size() - 2);
+        else if (header_string.ends_with("\n"))
+            header_string = header_string.substr(0, header_string.size() - 1);
+
+        header = map_io::header<std::vector<std::string>>{};
+        header.read(header_string);
     }
 
     auto const & get_header() const { return header; }