Added prefix to qt configure

.travis.yml

@@ -1,5 +1,6 @@
 language: cpp
 os: linux
+sudo: false
 dist: trusty
 compiler: gcc
 
@@ -12,14 +13,13 @@ before_script:
   - if [ ! -d qt5/.git ] ; then rm qt5 -Rf ; git clone --branch=5.10 git://code.qt.io/qt/qt5.git ; fi
   - pushd qt5
   - if [ ! -d qtbase/.git ] ; then perl init-repository --module-subset=qtbase,qtimageformats,qttools ; fi
-  - if [ ! -f config.summary ] ; then ./configure -opensource -confirm-license -nomake examples -nomake tests ; fi
-  - make -j2 > /dev/null
-  - sudo make install
+  - if [ ! -f config.summary ] ; then ./configure -prefix `pwd`/build -opensource -confirm-license -nomake examples -nomake tests ; fi
+  - if [ ! -d build ] ; then make -j2 > /dev/null && make install ; fi
   - popd
 
 script:
   - mkdir -p build
   - pushd build
-  - ../qt5/qtbase/bin/qmake .. -config release
+  - ../qt5/build/bin/qmake .. -config release
   - make -j2
   - popd