Trim Travis config part 3

- Only build & test two configurations. Make all the
  other build variants buildonly on gcc (clang on osx).
- Don't build with default clang at all on linux.
- Only use gcc-5 and clang-3.6 for the sanitizer builds. Re-running
  e.g. CONFIG_OPTS="shared" with them seems redundant.

Reviewed-by: Richard Levitte <levitte@openssl.org>

.travis.yml

@@ -18,18 +18,16 @@ os:
 
 compiler:
     - clang
-    - clang-3.6
     - gcc
-    - gcc-5
 
 env:
-    - CONFIG_OPTS=""
     - CONFIG_OPTS="shared"
-    - CONFIG_OPTS="no-pic"
     - CONFIG_OPTS="--debug --strict-warnings enable-crypto-mdebug enable-rc5 enable-md2"
+    - CONFIG_OPTS="" BUILDONLY="yes"
     - CONFIG_OPTS="--unified" BUILDONLY="yes"
     - CONFIG_OPTS="--unified shared" BUILDONLY="yes"
-    - CONFIG_OPTS="--unified --debug --strict-warnings enable-rc5 enable-md2" BUILDONLY="yes"
+    - CONFIG_OPTS="no-pic" BUILDONLY="yes"
+    - CONFIG_OPTS="no-engine" BUILDONLY="yes"
 
 matrix:
     include:
@@ -45,9 +43,6 @@ matrix:
         - os: linux
           compiler: gcc-5
           env: CONFIG_OPTS="no-asm --strict-warnings -fno-sanitize-recover -fsanitize=address -fsanitize=undefined enable-rc5 enable-md2"
-        - os: linux
-          compiler: clang
-          env: CONFIG_OPTS="no-engine" BUILDONLY="yes"
         - os: linux
           compiler: i686-w64-mingw32-gcc
           env: CONFIG_OPTS="no-pic"
@@ -55,12 +50,10 @@ matrix:
           compiler: x86_64-w64-mingw32-gcc
           env: CONFIG_OPTS="no-pic"
     exclude:
-        - os: osx
-          compiler: clang-3.6
+        - os: linux
+          compiler: clang
         - os: osx
           compiler: gcc
-        - os: osx
-          compiler: gcc-5
 
 before_script:
     - sh .travis-create-release.sh $TRAVIS_OS_NAME