Drop `make check` test log in $CHPL_HOME when it fails in smokeTest script.

Also, use $CHPL_HOME as root dir for creating a temp dir for copying/running
the hello*.chpl tests.
What env vars are sets in travis?
Revert "What env vars are sets in travis?"

This reverts commit 975f7104a2bd428acbc7fd6dae54d63c69fff928.
Update checkChplInstall to print error log when env var is set.

When CHPL_CHECK_INSTALL_PRINT_ERROR="true" is set and one or more tests fail,
checkChplInstall will now print the entire start_test log to stdout.
For travis builds, print start_test log when there are failures.

When travis builds fail, print the start_test log so users can see the actual
failures. Otherwise, they need to reproduce on another machine, which may or
may not be possible (especially if it is a platform specific issue).
temporarily break hello.chpl test to verify travis prints start_test log
Revert "temporarily break hello.chpl test to verify travis prints start_test log"

This reverts commit 09fd95074f0cb1a4c5ef2e93abf907871ba2e6fb.
Revert "Revert "temporarily break hello.chpl test to verify travis prints start_test log""

This reverts commit 1371b6c899d3058ae61a5b6a0c3e937881f9f5a9.
Revert "Revert "Revert "temporarily break hello.chpl test to verify travis prints start_test log"""

This reverts commit e16e184a857fd03743a7d474da5b9ea2ce04f44d.
Merge pull request #827 from thomasvandoren/keep-failure-log-in-chpl-home-for-smoke-test

Drop `make check` test log in $CHPL_HOME when it fails in smokeTest script.

Also, use $CHPL_HOME as root dir for creating a temp dir for copying/running
the hello*.chpl tests in smokeTest script.

r: @hildeth