tests: Add umockdev based testing

Initially only the vfs5011 driver is tested. Please note that these
tests will be unreliable before umockdev 0.13.2.

See also https://github.com/martinpitt/umockdev/pull/92

tests/capture.py

@@ -0,0 +1,46 @@
+#!/usr/bin/python3
+
+import gi
+gi.require_version('FPrint', '2.0')
+from gi.repository import FPrint, GLib
+import cairo
+import sys
+
+if len(sys.argv) != 2:
+    print("Please specify exactly one argument, the output location for the capture image")
+    sys.exit(1)
+
+ctx = GLib.main_context_default()
+
+c = FPrint.Context()
+c.enumerate()
+devices = c.get_devices()
+
+d = devices[0]
+
+d.open_sync()
+
+img = d.capture_sync(True)
+
+d.close_sync()
+
+width = img.get_width()
+height = img.get_height()
+
+c_img = cairo.ImageSurface(cairo.FORMAT_RGB24, width, height)
+
+c_rowstride = c_img.get_stride()
+
+buf = img.get_data()
+c_buf = c_img.get_data()
+
+for x in range(width):
+    for y in range(height):
+        c_buf[y * c_rowstride + x * 4 + 0] = buf[y * width + x]
+        c_buf[y * c_rowstride + x * 4 + 1] = buf[y * width + x]
+        c_buf[y * c_rowstride + x * 4 + 2] = buf[y * width + x]
+        # Byte 4 is don't care
+
+c_img.mark_dirty()
+c_img.write_to_png(sys.argv[1])
+