build: fix build on Fedora >26

Default QMake configuration in mingw packages has changed since
Fedora 26 and some modifications are required in order to make the
ring client able to compile on it:
 - GDI32 lib is now explicitely linked in our project file. It was
   previously done automatically by QMake "win32-g++" spec.
 - libpcre16-0.dll has been replaced by libpcre2-16-0.dll as a Qt
   dependency and must be shipped instead of the former one.
 - Dockerfile is updated for Fedora 27.

With this patch, the client shouldn't be able to compile anymore on
Fedora <26. Moreover, if building with "ring-project" facilities, a
patch is also required in that repository modifying the QMake selected
spec from "win32-g++" to "mingw-w64-g++".

Change-Id: I367312e66d790d82d6aa1aaa1ad3560e1abaca96
Reviewed-by: Olivier Soldano <olivier.soldano@savoirfairelinux.com>
diff --git a/RingWinClient.pro b/RingWinClient.pro
index a99ae12..d49d31f 100644
--- a/RingWinClient.pro
+++ b/RingWinClient.pro
@@ -155,7 +155,7 @@
     photoboothwidget.ui \
     deletecontactdialog.ui
 
-win32: LIBS += -lole32 -luuid -lshlwapi
+win32: LIBS += -lole32 -luuid -lshlwapi -lgdi32
 LIBS += -lqrencode
 
 INCLUDEPATH += $${RING}/include/libringclient
@@ -270,7 +270,7 @@
                             $$RUNTIMEDIR/libfreetype-6.dll $$RUNTIMEDIR/libglib-2.0-0.dll \
                             $$RUNTIMEDIR/libharfbuzz-0.dll \
                             $$RUNTIMEDIR/libintl-8.dll $$RUNTIMEDIR/libpcre-1.dll \
-                            $$RUNTIMEDIR/libpcre16-0.dll $$RUNTIMEDIR/libpng16-16.dll \
+                            $$RUNTIMEDIR/libpcre2-16-0.dll $$RUNTIMEDIR/libpng16-16.dll \
                             $$RUNTIMEDIR/libjpeg-62.dll $$RUNTIMEDIR/iconv.dll \
                             $$RUNTIMEDIR/libidn-11.dll $$RUNTIMEDIR/liblzma-5.dll \
                             $$RUNTIMEDIR/libGLESv2.dll $$RUNTIMEDIR/libbz2-1.dll \
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 810aace..6366173 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM fedora:25
+FROM fedora:27
 
 ENV LANG en_US.utf8
 ENV LC_ALL en_US.utf8
@@ -8,7 +8,8 @@
 # General
 RUN dnf -y install \
  unzip \
- openssh
+ openssh \
+ rsync
 
 # Mingw 32/64
 RUN dnf -y install \