BF: /opt/fmrib/fsl may not contain activate

child FSL environments will not contain activate so it must be provided by PATH instead.

unit_tests/utils/feedsRun.fslStartup

 #!/usr/bin/env fslpython
 
+#Note this script requires a conda activate script to be on the PATH
+
 import os
 import shlex
 import tempfile
@@ -32,7 +34,7 @@ def run(cmd, ompthreads=None, blasthreads=None, fslskipglobal=None):
 
 def main():
 
-    buildcmds = ['source $FSLDIR/bin/activate $FSLDIR',
+    buildcmds = ['source activate $FSLDIR',
                  'source $FSLDIR/etc/fslconf/fsl-devel.sh',
                  'make']
     sp.run('; '.join(buildcmds), check=True, shell=True)