Use only one machine for valgrind checks on ci

.travis.yml

@@ -6,23 +6,48 @@ matrix:
     - os: linux
       dist: trusty
       compiler: clang
+      env: T=normal
     - os: linux
       dist: trusty
       compiler: gcc
+      env: T=normal
     - os: linux
       dist: precise
       compiler: clang
+      env: T=normal
     - os: linux
       dist: precise
       compiler: gcc
+      env: T=normal
+    - os: linux
+      dist: precise
+      compiler: gcc
+      env: T=valgrind-check
+  allow_failures:
+    - os: linux
+      dist: precise
+      compiler: gcc
+      env: T=valgrind-check
 
 sudo: required
 
 before_install:
   - sudo apt-get update --quiet --assume-yes
   - sudo apt-get install splint --quiet --assume-yes
-  - sudo apt-get install valgrind --quiet --assume-yes
+  - if [[ "$T" = "valgrind-check" ]]; then apt-get install valgrind --quiet --assume-yes; fi
 
 before_script: ./autogen.sh
 script:
-  - ./autogen.sh && ./configure --disable-shared && make ci
+  - |
+      if [ "$T" = "normal" ]; then
+           ./autogen.sh
+           ./configure --disable-shared
+           make
+           make test
+      fi
+  - |
+      if [ "$T" = "valgrind-check" ]; then
+           ./autogen.sh
+           ./configure --disable-shared
+           make ci
+      fi