Add support for snaps.

Work done by William Hua and Robert Ancell.

https://bugzilla.gnome.org/show_bug.cgi?id=767673

src/plugins/Makefile.am

@@ -42,7 +42,8 @@ plugin_LTLIBRARIES =					\
 	libgs_plugin_provenance-license.la		\
 	libgs_plugin_fedora-tagger-usage.la		\
 	libgs_plugin_epiphany.la			\
-	libgs_plugin_icons.la
+	libgs_plugin_icons.la				\
+	libgs_plugin_snap.la
 
 if HAVE_PACKAGEKIT
 plugin_LTLIBRARIES +=					\
@@ -328,6 +329,17 @@ libgs_plugin_packagekit_proxy_la_LIBADD = $(GS_PLUGIN_LIBS)
 libgs_plugin_packagekit_proxy_la_LDFLAGS = -module -avoid-version
 libgs_plugin_packagekit_proxy_la_CFLAGS = $(GS_PLUGIN_CFLAGS) $(WARN_CFLAGS)
 
+libgs_plugin_snap_la_SOURCES =				\
+	gs-plugin-snap.c				\
+	gs-snapd.h					\
+	gs-snapd.c
+libgs_plugin_snap_la_LIBADD =				\
+	$(GS_PLUGIN_LIBS)				\
+	$(SOUP_LIBS)					\
+	$(JSON_GLIB_LIBS)
+libgs_plugin_snap_la_LDFLAGS = -module -avoid-version
+libgs_plugin_snap_la_CFLAGS = $(GS_PLUGIN_CFLAGS) $(WARN_CFLAGS)
+
 if ENABLE_TESTS
 check_PROGRAMS =						\
 	gs-self-test