Separate integration tests; simplify test scripts (#4006)

* Separate build integration tests; simplify test scripts

- Move build tests out of the regular Travis unit tests, add more smoke
  test packages to build.

- Run all test scripts with bash -e, which fails on error.

- Factor coverage out into a Travis environment variable, so it's more
  obvious from .travis.yml which tests contribute to coverage and which
  don't.

- Factor dependency checking and much of the front-matter in tests
  scripts into a setup.sh script, which is sourced by all the test
  scripts.  Extra cruft in each tests script now reduced to 2 lines at
  the beginning.

.travis.yml

@@ -21,7 +21,11 @@ matrix:
     - python: '2.7'
       os: linux
       language: python
-      env: TEST_SUITE=unit
+      env: [ TEST_SUITE=unit, COVERAGE=true ]
+    - python: '2.7'
+      os: linux
+      language: python
+      env: [ TEST_SUITE=build, COVERAGE=true, 'SPEC=hypre^mpich' ]
     - python: '3.3'
       os: linux
       language: python
@@ -37,7 +41,11 @@ matrix:
     - python: '3.6'
       os: linux
       language: python
-      env: TEST_SUITE=unit
+      env: [ TEST_SUITE=unit, COVERAGE=true ]
+    - python: '3.6'
+      os: linux
+      language: python
+      env: [ TEST_SUITE=build, COVERAGE=true, 'SPEC=hypre^mpich' ]
     - python: '2.7'
       os: linux
       language: python
@@ -48,7 +56,7 @@ matrix:
       env: TEST_SUITE=doc
     - os: osx
       language: generic
-      env: [ TEST_SUITE=unit, PYTHON_VERSION=2.7 ]
+      env: [ TEST_SUITE=unit, PYTHON_VERSION=2.7, COVERAGE=true ]
 
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 # Environment