Compiler detection failure on Ubuntu 16.04

[eddelbuettel]

Notice on https://rstudio.cloud:

checking whether g++ version is sufficient... almost
configure: WARNING: Compiler self-identifies as being compliant with GNUC extensions but is not g++.
checking LAPACK_LIBS... system LAPACK found

yet

$ g++ -v 2>&1 | awk '/^.*g.. version/ {print $3}'
5.4.0
$ 

Fix forthcoming.

[eddelbuettel]

And yes /bin/sh is /bin/dash there.