[tepl] Use GtkSourceView 4

[Sébastien Wilmet <swilmet src gnome org>]

commit 030647a29c29712109495c6a4ecf7f84ea43d822
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Oct 26 16:16:10 2017 +0200

    Use GtkSourceView 4

 README       |    4 ++--
 configure.ac |    6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/README b/README
index 0c294b1..05b361c 100644
--- a/README
+++ b/README
@@ -21,8 +21,8 @@ Dependencies
 ------------
 
 - GLib >= 2.52
-- GTK+ >= 3.20
-- GtkSourceView >= 3.22
+- GTK+ >= 3.22
+- GtkSourceView >= 3.99.6
 - libxml2 >= 2.5
 - uchardet
 
diff --git a/configure.ac b/configure.ac
index 871b53e..fb17546 100644
--- a/configure.ac
+++ b/configure.ac
@@ -57,8 +57,8 @@ AC_SUBST(TEPL_API_VERSION)
 
 # Dependencies
 glib_req=2.52
-gtk_req=3.20
-gtksourceview_req=3.22
+gtk_req=3.22
+gtksourceview_req=3.99.6
 libxml_req=2.5
 
 AC_CONFIG_SRCDIR([tepl/tepl.h])
@@ -100,7 +100,7 @@ AX_PKG_CHECK_MODULES([AMTK_DEP],
                     [AMTK_PACKAGE_REQUIRES_PRIVATE])
 
 AX_PKG_CHECK_MODULES([TEPL_DEP],
-                    [glib-2.0 >= $glib_req  gtk+-3.0 >= $gtk_req  gtksourceview-3.0 >= $gtksourceview_req],
+                    [glib-2.0 >= $glib_req  gtk+-3.0 >= $gtk_req  gtksourceview-4 >= $gtksourceview_req],
                     [libxml-2.0 >= $libxml_req  uchardet],
                     [], [],
                     [TEPL_PACKAGE_REQUIRES],