non-parallel regression tester doesn't use robot for resolving dependencies

[boegel]

When using the regression tester script regtest.py in non-parallel mode, the robot feature for resolving dependencies is not being used, and hence the builds may fails because of missing dependencies.

Example use case:

./easybuild/scripts/regtest.py --no-parallel -r easybuild/easyconfigs easybuild/easyconfigs/i/ictce

which results in:

== 2012-08-26 08:30:37,529 Toolkit ERROR EasyBuild crashed with an error (at easybuild/tools/build_log.py:64 in callerInfo): No module found for dependency icc/2011.6.233
== 2012-08-26 08:30:37,529 ParallelBuild INFO <easybuild.easyblocks.toolkit.EB_Toolkit instance at 0x9d2878> crashed with an error during fase: pre-build verification, error: 'EasyBuild crashed with an error (at easybuild/tools/build_log.py:64 in callerInfo): No module found for dependency icc/11.1.073-32bit'
== 2012-08-26 08:30:37,530 ParallelBuild INFO <easybuild.easyblocks.toolkit.EB_Toolkit instance at 0x9d5248> crashed with an error during fase: pre-build verification, error: 'EasyBuild crashed with an error (at easybuild/tools/build_log.py:64 in callerInfo): No module found for dependency icc/11.1.073'
== 2012-08-26 08:30:37,530 ParallelBuild INFO <easybuild.easyblocks.toolkit.EB_Toolkit instance at 0x9d63f8> crashed with an error during fase: pre-build verification, error: 'EasyBuild crashed with an error (at easybuild/tools/build_log.py:64 in callerInfo): No module found for dependency icc/2011.6.233'

even though these dependencies can be resolved with the supplied robot path.

[boegel]

should be fixed together with #154