Have Travis print out build logs in case of test failures

To get the after_failure line work, I had to move the inline
build script to a separate script (util/travis-script.sh)

The second script (util/travis-after-failure.sh) will output
LastTest.log for cmake based builds and all files named
test*.log for an autotools based build.

Note: this commit also comes with a delibarate test failure
to illustrate the Travis behaviour. It will be removed in the
next commit.

util/travis-after-failure.sh

@@ -0,0 +1,19 @@
+#! /bin/bash
+
+# Build logs are located in different places depending on the build environment used
+if [[ "$BUILDTYPE" == "cmake-make" ]] || [[ "$BUILDTYPE" == "cmake-ninja" ]]; then
+  echo "##### LastTest.log #####"
+  echo "#########################"
+  cat /tmp/gnucash-build-${BUILDTYPE}/Testing/Temporary/LastTest.log
+elif [[ "$BUILDTYPE" == "autotools" ]]; then
+  for logfile in $( find . -name 'test*.log' ); do
+    SIZE=$((${#logfile} + 12))
+    HRULE=$(head -c $SIZE < /dev/zero | tr '\0' '#')
+    echo $HRULE
+    echo "##### ${logfile} #####"
+    echo $HRULE
+    cat -- "$logfile"
+    echo -e "\n\n"
+  done
+fi
+

util/travis-script.sh

@@ -0,0 +1,30 @@
+#! /bin/bash -ev
+# The -e above says that if any line below fails, the whole script fails
+
+# Run tests in different build configurations depending on the
+# value of the BUILDTYPE environment variable
+# 1. cmake build using the default Makefile generator
+if [[ "$BUILDTYPE" == "cmake-make" ]]; then
+  mkdir /tmp/gnucash-build-cmake-make
+  cd /tmp/gnucash-build-cmake-make
+  cmake $TRAVIS_BUILD_DIR
+  make -j 4
+  make check
+
+# 2. cmake build using the Ninja generator
+elif [[ "$BUILDTYPE" == "cmake-ninja" ]]; then
+  mkdir /tmp/gnucash-build-cmake-ninja
+  cd /tmp/gnucash-build-cmake-ninja
+  cmake -G Ninja $TRAVIS_BUILD_DIR
+  ninja
+  ninja check
+
+# 3. autotools build
+elif [[ "$BUILDTYPE" == "autotools" ]]; then
+  cd $TRAVIS_BUILD_DIR
+  ./autogen.sh
+  ./configure
+  make
+  make check
+fi
+