[travis] Install CMake 3.11

Remove check_include_files from FindODBC.cmake module -
it is hard to get check_include_files right, even possible
it should not be used in Find*.cmake.

[skip appveyor]

.travis.yml

@@ -32,17 +32,11 @@ env:
     - SOCI_TRAVIS_BACKEND=oracle WITH_BOOST=OFF
 
 addons:
-  apt:
-    sources:
-      - ubuntu-toolchain-r-test
-      - sourceline: 'ppa:roblib/ppa'
-    packages:
-      - cmake
   coverity_scan:
     project:
       name: "SOCI/soci"
     notification_email: soci-devel@lists.sourceforge.net
-    build_command_prepend: "mkdir build.cov; cd build.cov; cmake .."
+    build_command_prepend: "sh ${TRAVIS_BUILD_DIR}/scripts/travis/install_cmake.sh; mkdir build.cov; cd build.cov; cmake .."
     build_command: "make -j 4"
     branch_pattern: coverity_scan
 

cmake/modules/FindODBC.cmake

@@ -17,25 +17,21 @@
 # ODBC_LIBRARY, where to find the ODBC driver manager library.
 
 set(ODBC_FOUND FALSE)
-include(CheckIncludeFiles)
-check_include_files("windows.h;sqlext.h" HAVE_SQLEXT_H)
 
-if(NOT HAVE_SQLEXT_H)
-  find_path(ODBC_INCLUDE_DIR sqlext.h
-    /usr/include
-    /usr/include/odbc
-    /usr/local/include
-    /usr/local/include/odbc
-    /usr/local/odbc/include
-    "C:/Program Files (x86)/Windows Kits/8.0/include/um"
-    "C:/Program Files (x86)/Microsoft SDKs/Windows/v7.0A/Include"
-    "C:/Program Files/ODBC/include"
-    "C:/Program Files/Microsoft SDKs/Windows/v7.0/include"
-    "C:/Program Files/Microsoft SDKs/Windows/v6.0a/include"
-    "C:/ODBC/include"
-    DOC "Specify the directory containing sql.h."
-  )
-endif()
+find_path(ODBC_INCLUDE_DIR sqlext.h
+  /usr/include
+  /usr/include/odbc
+  /usr/local/include
+  /usr/local/include/odbc
+  /usr/local/odbc/include
+  "C:/Program Files (x86)/Windows Kits/8.0/include/um"
+  "C:/Program Files (x86)/Microsoft SDKs/Windows/v7.0A/Include"
+  "C:/Program Files/ODBC/include"
+  "C:/Program Files/Microsoft SDKs/Windows/v7.0/include"
+  "C:/Program Files/Microsoft SDKs/Windows/v6.0a/include"
+  "C:/ODBC/include"
+  DOC "Specify the directory containing sql.h."
+)
 
 if(MSVC)
     # msvc knows where to find sdk libs

scripts/travis/before_install.sh

@@ -13,6 +13,8 @@ sudo apt-get install -qq -y apt-fast
 sudo apt-fast update -qq -y
 sudo apt-fast install -qq -y libboost-dev libboost-date-time-dev valgrind
 
+sh ${TRAVIS_BUILD_DIR}/scripts/travis/install_cmake.sh
+
 before_install="${TRAVIS_BUILD_DIR}/scripts/travis/before_install_${SOCI_TRAVIS_BACKEND}.sh"
 if [ -x ${before_install} ]; then
 	echo "Running ${before_install}"

scripts/travis/install_cmake.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+set -x
+
+wget -q https://cmake.org/files/v3.11/cmake-3.11.0-Linux-x86_64.sh
+sudo sh cmake-3.11.0-Linux-x86_64.sh -- --skip-license --prefix=/usr/local
+cmake --version