Add missing fastavro/_logical_writers.c to Makefile
@@ -12,7 +12,7 @@ endif
%.c: %.pyx
cython $(<D)/$(<F)
-c_files = fastavro/_six.c fastavro/_read.c fastavro/_write.c fastavro/_schema.c fastavro/_validation.c
+c_files = fastavro/_six.c fastavro/_read.c fastavro/_write.c fastavro/_schema.c fastavro/_validation.c fastavro/_logical_writers.c
all: $(c_files)
