ci: update Travis-CI configuration

 * Re-enable ASan with gcc-7
 * Add clang-6.0 to the build matrix (allowed to fail)
 * Remove unsupported OSX-10.10 configuration
 * Upgrade xcode9 to xcode9.2
 * Add testing of openssl 1.1 on osx (allowed to fail)
 * Various simplifications

Change-Id: I3cdfcf78e6a9be66d1063fee710528698ad90bca
diff --git a/.jenkins.d/10-build.sh b/.jenkins.d/10-build.sh
index 6844e93..fe2bfa0 100755
--- a/.jenkins.d/10-build.sh
+++ b/.jenkins.d/10-build.sh
@@ -11,19 +11,28 @@
 sudo rm -f /usr/local/lib/libndn-cxx*
 sudo rm -f /usr/local/lib/pkgconfig/libndn-cxx.pc
 
+if [[ $JOB_NAME == *"code-coverage" ]]; then
+    COVERAGE="--with-coverage"
+elif [[ -z $DISABLE_ASAN ]]; then
+    ASAN="--with-sanitizer=address"
+fi
+if [[ -n $USE_OPENSSL_1_1 ]] && has OSX $NODE_LABELS; then
+    OPENSSL="--with-openssl=/usr/local/opt/openssl@1.1"
+fi
+
 # Cleanup
 sudo env "PATH=$PATH" ./waf --color=yes distclean
 
 if [[ $JOB_NAME != *"code-coverage" && $JOB_NAME != *"limited-build" ]]; then
   # Configure/build static library in optimized mode with tests
-  ./waf --color=yes configure --enable-static --disable-shared --with-tests
+  ./waf --color=yes configure --enable-static --disable-shared --with-tests $OPENSSL
   ./waf --color=yes build -j${WAF_JOBS:-1}
 
   # Cleanup
   sudo env "PATH=$PATH" ./waf --color=yes distclean
 
   # Configure/build static and shared library in optimized mode without tests
-  ./waf --color=yes configure --enable-static --enable-shared
+  ./waf --color=yes configure --enable-static --enable-shared $OPENSSL
   ./waf --color=yes build -j${WAF_JOBS:-1}
 
   # Cleanup
@@ -31,12 +40,8 @@
 fi
 
 # Configure/build shared library in debug mode with tests/examples and without precompiled headers
-if [[ $JOB_NAME == *"code-coverage" ]]; then
-    COVERAGE="--with-coverage"
-elif [[ -n $BUILD_WITH_ASAN || -z $TRAVIS ]]; then
-    ASAN="--with-sanitizer=address"
-fi
-./waf --color=yes configure --disable-static --enable-shared --debug --with-tests --with-examples --without-pch $COVERAGE $ASAN
+./waf --color=yes configure --disable-static --enable-shared --debug --with-tests \
+                            --with-examples --without-pch $ASAN $COVERAGE $OPENSSL
 ./waf --color=yes build -j${WAF_JOBS:-1}
 
 # (tests will be run against debug version)