Set pipefail for Cram tests

This was added in places where it's been necessary. Setting it globally
simplifies tests and allows future tests to use pipes without the need
to set pipefail explicitly.

.cramrc

@@ -1,3 +1,3 @@
 [cram]
-shell = /bin/bash
+shell = /bin/bash -o pipefail
 indent = 2

tests/functional/curate/cram/validate-records.t

@@ -25,7 +25,6 @@ error when it encounters the record with mismatched fields.
 Passing the records through multiple augur curate commands should raise the
 same error when it encounters the record with mismatched fields.
 
-  $ set -o pipefail
   $ cat records.ndjson \
   >   | ${AUGUR} curate passthru \
   >   | ${AUGUR} curate passthru \

tests/functional/merge/cram/merge.t

@@ -1,7 +1,6 @@
 SETUP
 
   $ export AUGUR="${AUGUR:-$TESTDIR/../../../../bin/augur}"
-  $ set -o pipefail
 
 
 BASIC USAGE