Readme: use flatpak builder (#277)

README.md

@@ -7,27 +7,14 @@ The camera app designed for elementary OS
 
 ## Building, Testing, and Installation
 
-You'll need the following dependencies:
+Run `flatpak-builder` to configure the build environment, download dependencies, build, and install
 
- - gstreamer1.0-gtk3
- - libcanberra-dev
- - libclutter-gst-3.0-dev
- - libclutter-gtk-1.0-dev
- - libgranite-dev
- - libgstreamer1.0-dev
- - libgstreamer-plugins-base1.0-dev
- - libgtk-3-dev
- - libhandy-1-dev
- - meson >= 0.46
- - valac
+```bash
+    flatpak-builder build io.elementary.camera.yml --user --install --force-clean --install-deps-from=appcenter
+```
 
-Run `meson build` to configure the build environment. Change to the build directory and run `ninja test` to build and run automated tests
+Then execute with
 
-    meson build --prefix=/usr
-    cd build
-    ninja test
-
-To install, use `ninja install`, then execute with `io.elementary.camera`
-
-    sudo ninja install
-    io.elementary.camera
+```bash
+    flatpak run io.elementary.camera
+```