message: construction_worker: added task to check amalgamation
  Builds and runs test cases from individual sources rather than from amalgamation.
  Checks whether amalgamation would create the same single-header file as checked in.
diff: @@ -74,6 +74,20 @@ matrix:
  sources: ['ubuntu-toolchain-r-test']
  packages: ['g++-4.9', 'ninja-build']
  + # check amalgamation
  + - os: linux
  + compiler: gcc
  + env:
  + - COMPILER=g++-4.9
  + - SPECIAL=amalgamation
  + - CMAKE_OPTIONS=-DJSON_MultipleHeader=ON
  + addons:
  + apt:
  + sources: ['ubuntu-toolchain-r-test']
  + packages: ['g++-4.9', 'astyle', 'ninja-build']
  + after_success:
  + - make check-amalgamation
  +
  # Coveralls (http://gronlier.fr/blog/2015/01/adding-code-coverage-to-your-c-project/)
  - os: linux
  