Handle decimal conversion error in test case
Handle decimal conversion error in test case

Some test case operations involving measurements can convert
to a decimal which is not suitable for database storage. Catch
the exception to allow the master to continue, logging the
exception.

Change-Id: Ic0e82795e800ec5320e572d3cde58742b5d490b5

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server