travis-ci: upgrade version numbers of NGINX core and openssl, remove clang compiler mode from travis to save credits. (#62)

Author: xiaocang

.travis.yml

@@ -7,7 +7,6 @@ language: c
 
 compiler:
   - gcc
-  - clang
 
 addons:
   apt:
@@ -32,12 +31,12 @@ env:
     - OPENSSL_PREFIX=/opt/ssl
     - OPENSSL_LIB=$OPENSSL_PREFIX/lib
     - OPENSSL_INC=$OPENSSL_PREFIX/include
-    - OPENSSL_VER=1.0.2h
+    - OPENSSL_VER=1.1.1k
     - LD_LIBRARY_PATH=$LUAJIT_LIB:$LD_LIBRARY_PATH
     - TEST_NGINX_SLEEP=0.006
   matrix:
-    - NGINX_VERSION=1.9.15
-    - NGINX_VERSION=1.19.3
+    - NGINX_VERSION=1.17.8
+    - NGINX_VERSION=1.19.9
 
 install:
   - if [ ! -d download-cache ]; then mkdir download-cache; fi