add cmake 3.8.1 testing (#172)

* add cmake 3.8.1 to travis testing
* update docs with cmake ver recs

.travis.yml

@@ -55,17 +55,43 @@ env:
     # we need to know the root dir for our 3rd party lib installs
     - TRAVIS_HOME=`pwd`
   matrix:
-    # we want to test both static and shared
-    # and python 2 + 3
+    #################################
+    # we are testing:
+    #  static vs shared libs
+    #  python 2 vs 3
+    #  cmake 3.3.0 vs 3.8.1
+    #  coverage of unit tests
+    #################################
+    # cmake 3.3.1 + shared libs + python 2 + coverage
     - BUILD_SHARED_LIBS=ON
       MINICONDA=Miniconda2
       ENABLE_COVERAGE=ON
+      CMAKE_MAJOR=3.3
+      CMAKE_MINOR=1
+    # cmake 3.3.1 + static libs + python 2
+    - BUILD_SHARED_LIBS=OFF
+      MINICONDA=Miniconda2
+      ENABLE_COVERAGE=OFF
+      CMAKE_MAJOR=3.3
+      CMAKE_MINOR=1
+    # cmake 3.3.1 + shared libs + python 3
     - BUILD_SHARED_LIBS=ON
       MINICONDA=Miniconda3
       ENABLE_COVERAGE=OFF
+      CMAKE_MAJOR=3.3
+      CMAKE_MINOR=1
+    # cmake 3.8.1 + shared libs + python 2
+    - BUILD_SHARED_LIBS=ON
+      MINICONDA=Miniconda2
+      ENABLE_COVERAGE=OFF
+      CMAKE_MAJOR=3.8
+      CMAKE_MINOR=1
+    # cmake 3.8.1 + static libs + python 2
     - BUILD_SHARED_LIBS=OFF
       MINICONDA=Miniconda2
       ENABLE_COVERAGE=OFF
+      CMAKE_MAJOR=3.8
+      CMAKE_MINOR=1
 addons:
   apt:
     sources:
@@ -75,22 +101,26 @@ addons:
        - g++-4.8
        - gfortran-4.8
 before_install:
-  # download a newer version of cmake
-  - wget --no-check-certificate http://www.cmake.org/files/v3.3/cmake-3.3.0-Linux-x86_64.sh
+  # download the ver of cmake we want to test
+  - wget --no-check-certificate http://www.cmake.org/files/v${CMAKE_MAJOR}/cmake-${CMAKE_MAJOR}.${CMAKE_MINOR}-Linux-x86_64.sh
+  # download miniconda (used get python, numpy, and hdf5)
+  - wget --no-check-certificate http://repo.continuum.io/miniconda/${MINICONDA}-latest-Linux-x86_64.sh -O miniconda.sh
+install:
+  # install cmake
   - mkdir ${TRAVIS_HOME}/cmake/
+  - sh cmake-${CMAKE_MAJOR}.${CMAKE_MINOR}-Linux-x86_64.sh --skip-license --prefix=${TRAVIS_HOME}/cmake/
   - export PATH=${TRAVIS_HOME}/cmake/bin:$PATH
-  # prep to use miniconda to get python and numpy
-  - wget --no-check-certificate http://repo.continuum.io/miniconda/${MINICONDA}-latest-Linux-x86_64.sh -O miniconda.sh
+  # install + update miniconda
   - chmod +x miniconda.sh
   - ./miniconda.sh -b -p ${TRAVIS_HOME}/miniconda
   - export PATH=${TRAVIS_HOME}/miniconda/bin:$PATH
   - conda update --yes conda
-install:
-  - sh cmake-3.3.0-Linux-x86_64.sh --skip-license --prefix=${TRAVIS_HOME}/cmake/
+  # install numpy + hdf5 and the coveralls python package
   - conda install --yes numpy
   - conda install --yes hdf5
   - pip install cpp-coveralls
 script:
+  # echo cmake version
   - cmake --version
   - cd $TRAVIS_BUILD_DIR
   # create out-of-source build dir, and an install dir

src/docs/sphinx/building.rst

@@ -299,6 +299,11 @@ Variants are enabled using ``+`` and disabled using ``~``. For example, to build
   spack install conduit~python~mpi~hdf5~silo~docs
 
 
+Supported CMake Versions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+We test building Conduit with CMake 3.3.1 and 3.8.1. Other versions of CMake may work, however CMake 3.4.x to 3.7.x have specific issues with finding and using HDF5 and Python.
+
+
 
 Using Conduit in Another Project
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~