Travis CI: Remove builds with Sage binary distributions that have been deleted

Author: Matthias Koeppe

.travis.yml

@@ -7,12 +7,6 @@ matrix:
   include:
   - env: CACHE_NAME=7.6 DEPLOY_DOC_FROM_BRANCH=master DEPLOY_DOC_TO_DIRECTORY=/ SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.6-Ubuntu_12.04-x86_64.tar.bz2
   - env: CACHE_NAME=7.5.1 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.5.1-Ubuntu_12.04-x86_64.tar.bz2
-  - env: CACHE_NAME=7.4 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.4-Ubuntu_12.04-x86_64.tar.bz2
-  - env: CACHE_NAME=7.3 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.3-Ubuntu_12.04-x86_64.tar.bz2
-  - env: CACHE_NAME=7.2 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.2-Ubuntu_12.04-x86_64.tar.bz2
-  - env: CACHE_NAME=7.1 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.1-Ubuntu_12.04-x86_64.tar.bz2
-  allow_failures:
-  - env: CACHE_NAME=7.1 SAGE_SERVER=http://mirrors.xmission.com/sage/ SAGE_IMAGE=linux/64bit/sage-7.1-Ubuntu_12.04-x86_64.tar.bz2
 install:
 - ./.travis-install.sh
 script: