Fixed issue when passing absolute path to script (#2518)
Fixed issue when passing absolute path to script (#2518)

* sct_run_batch.sh input params path fix

* sct_run_batch: Simplified way to get absolute path

* sct_run_batch: Now checking for file existence


Former-commit-id: 9d879c8059d59e7d02a0ed835e442f116dec35dd
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox