Fix compilation issues with standard includes

src/mimetype.c

diff --git a/src/mimetype.c b/src/mimetype.c
index 53af0af..833ddc7 100644
--- a/src/mimetype.c
+++ b/src/mimetype.c
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <sys/stat.h>
 
 #include <glib.h>

src/service.c

diff --git a/src/service.c b/src/service.c
index 1f346fc..4d9ebfd 100644
--- a/src/service.c
+++ b/src/service.c
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>
+#include <stdlib.h>
 
 #include <glib.h>
 

src/transport.c

diff --git a/src/transport.c b/src/transport.c
index 5347b07..4984643 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>
+#include <stdlib.h>
 
 #include <glib.h>