lib/actors: uniformize Makefile names with the rest of the Nit project

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/lib/actors/examples/chameneos-redux/makefile b/lib/actors/examples/chameneos-redux/Makefile
similarity index 100%
rename from lib/actors/examples/chameneos-redux/makefile
rename to lib/actors/examples/chameneos-redux/Makefile

diff --git a/lib/actors/examples/fannkuchredux/makefile b/lib/actors/examples/fannkuchredux/Makefile
similarity index 100%
rename from lib/actors/examples/fannkuchredux/makefile
rename to lib/actors/examples/fannkuchredux/Makefile

diff --git a/lib/actors/examples/mandelbrot/makefile b/lib/actors/examples/mandelbrot/Makefile
similarity index 100%
rename from lib/actors/examples/mandelbrot/makefile
rename to lib/actors/examples/mandelbrot/Makefile

diff --git a/lib/actors/examples/simple/makefile b/lib/actors/examples/simple/Makefile
similarity index 100%
rename from lib/actors/examples/simple/makefile
rename to lib/actors/examples/simple/Makefile