CI: Install some more dependencies in CI env

.ci/create_dev_env.sh

+#!/usr/bin/env bash
+
+envdir=${1}
+
+channels=(-c https://fsl.fmrib.ox.ac.uk/fsldownloads/fslconda/development/
+          -c https://fsl.fmrib.ox.ac.uk/fsldownloads/fslconda/public/
+          -c conda-forge)
+
+conda create -y ${channels[@]}   \
+      -p ./${envdir}             \
+      "python=${PYTHON_VERSION}" \
+      pytest                     \
+      coverage                   \
+      pytest-cov                 \
+      fsl-avwutils               \
+      fsl-pyfix                  \
+      file-tree file-tree-fsl    \
+      fsl_sub                    \
+      fsl_sub_plugin_slurm       \
+      fsl_sub_plugin_sge
+
+source activate ${envdir}
+pip install dmri-amico
+pip install git+https://git.fmrib.ox.ac.uk/ndcn0236/pipe-tree.git

.ci/unit_tests.sh

 #!/usr/bin/env bash
 
-conda create                                                      \
-      -c https://fsl.fmrib.ox.ac.uk/fsldownloads/fslconda/public/ \
-      -c conda-forge                                              \
-      -p ./test.env                                               \
-      "python=${PYTHON_VERSION}"                                  \
-      pytest                                                      \
-      coverage                                                    \
-      pytest-cov
+thisdir=$(cd $(dirname $0) & pwd)
+
+${thisdir}/create_dev_env.sh ./test.env
 
 source activate ./test.env
+export FSLDIR=$CONDA_PREFIX
+source $FSLDIR/etc/fslconf/fsl.sh
 
 pip install --no-deps -e .