Try different Travis boost install approach

Source: microsoft/bond@87b87e4

Author: tomchadwin

.travis.yml

@@ -5,6 +5,8 @@ sudo: true
 dist: trusty
 addons:
   apt:
+    sources:
+    - sourceline: 'ppa:kzemek/boost'
     packages:
     - liblua5.1-0
     - liblua5.1-0-dev
@@ -13,12 +15,9 @@ addons:
     - protobuf-compiler
     - shapelib
     - libshp-dev
-install:
-  - sudo add-apt-repository -y ppa:ostogvin/tjo-develop
-  - sudo apt-get update
-  - sudo apt-get install libboost1.58-dev
-  - sudo apt-get install libboost-program-options1.58
-  - sudo apt-get install libboost-filesystem1.58-dev
-  - sudo apt-get install libboost-system1.58
+    - libboost1.58-dev
+    - libboost-program-options1.58
+    - libboost-filesystem1.58-dev
+    - libboost-system1.58
 script:
   - make -j2