[Travis] try using boost from a different ppa

mwarusz · mwarusz · commit 056310be6191 · 2019-01-11T17:36:48.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -37,9 +37,9 @@ addons:
     packages:
       - g++-6
       - clang-4.0
-      - boost1.67
+      - boost1.61
     sources: &sources
-      - sourceline: 'ppa:mhier/libboost-latest'
+      - sourceline: 'ppa:rakhimov/boost'
       - ubuntu-toolchain-r-test
       - llvm-toolchain-trusty-4.0
 
