Update Travis.yml + gitignore

.gitignore

@@ -1,2 +1,5 @@
 # QtCreater generated file
 CMakeLists.txt.user
+
+# build folders
+/build-*

.travis.yml

@@ -124,12 +124,21 @@ before_install:
     - eval "${MATRIX_EVAL}"
     - export CC=${CC}
     - export CXX=${CXX}
-    - echo "CC = ${CC} $(${CC} -dumpversion)"
-    - echo "CXX = ${CXX} $(${CXX} -dumpversion)"
     - export ENABLE_OMP=${ENABLE_OMP}
     - export ENABLE_TBB=${ENABLE_TBB}
     - export ENABLE_SSE=${ENABLE_SSE}
     - export CXXSTD=${CXXSTD}
+    - export PYBINPATH=$(dirname $(which python))
+    - export PYROOTPATH=$(dirname ${PYBINPATH})
+    - export PATH=${PYBINPATH}:${PATH}
+    - export CMAKE_PREFIX_PATH=${PYROOTPATH}:${CMAKE_PREFIX_PATH}
+    - export PYTHON_VERSION="$(python --version | awk '{print $NF}')"
+    - echo "CC = ${CC} $(${CC} -dumpversion)"
+    - echo "CXX = ${CXX} $(${CXX} -dumpversion)"
+    - echo "Python = $(which python) [version ${PYTHON_VERSION}]"
+    - echo "PYBINPATH = ${PYBINPATH}"
+    - echo "PYROOTPATH = ${PYROOTPATH}"
+    - echo "CMAKE_PREFIX_PATH = ${CMAKE_PREFIX_PATH}"
 
 install:
     - env
@@ -145,7 +154,7 @@ install:
         -DBUILD_CXXSTD=${CXXSTD} -DENABLE_UNIT_TEST=ON
         -DUSE_TBB=${ENABLE_TBB} -DUSE_OPENMP=${ENABLE_OMP}
         -DUSE_TCMALLOC=OFF -DUSE_SSE=${ENABLE_SSE}
-        -DUSE_PYBIND11=ON ${PWD}/..
+        -DUSE_PYBIND11=ON -DPYTHON_EXECUTABLE=$(which python) ${PWD}/..
     - grep '^[A-Za-z]' CMakeCache.txt | grep -vi advanced
     - make -j2