Travis: make a separate job for external tests

Some of the external tests do not run well with 'no-shared'
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3007)

.travis.yml

@@ -71,7 +71,17 @@ matrix:
                   sources:
                       - ubuntu-toolchain-r-test
           compiler: gcc-5
-          env:  EXTENDED_TEST="yes" CONFIG_OPTS="--debug --coverage no-asm enable-rc5 enable-md2 enable-ec_nistp_64_gcc_128 enable-ssl3 enable-ssl3-method enable-nextprotoneg enable-weak-ssl-ciphers enable-external-tests no-shared -DPEDANTIC -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION" COVERALLS="yes" BORINGSSL_TESTS="yes" CXX="g++-5"
+          env:  EXTENDED_TEST="yes" CONFIG_OPTS="--debug --coverage no-asm enable-rc5 enable-md2 enable-ec_nistp_64_gcc_128 enable-ssl3 enable-ssl3-method enable-nextprotoneg enable-weak-ssl-ciphers no-shared -DPEDANTIC -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION" COVERALLS="yes" BORINGSSL_TESTS="yes" CXX="g++-5"
+        - os: linux
+          addons:
+              apt:
+                  packages:
+                      - gcc-5
+                      - g++-5
+                  sources:
+                      - ubuntu-toolchain-r-test
+          compiler: gcc-5
+          env:  EXTENDED_TEST="yes" CONFIG_OPTS="--debug enable-ssl3 enable-ssl3-method enable-weak-ssl-ciphers enable-external-tests" BORINGSSL_TESTS="yes" CXX="g++-5" TESTS=95
         - os: linux
           addons:
               apt: