BLD: unshallow the travis git checkout so conda build can clone it

.travis.yml

@@ -25,6 +25,7 @@ before_install:
   - sed -i "s/scipy==.*/scipy==$SCIPY_VERSION/" etc/requirements.txt
 install:
   - conda install conda-build --yes
+
   - conda create -n testenv --yes -c quantopian pip python=$TRAVIS_PYTHON_VERSION numpy=$NUMPY_VERSION scipy=$SCIPY_VERSION libgfortran=1.0 ta-lib=0.4.9
   - source activate testenv
   - pip install --upgrade pip coverage coveralls --cache-dir=$CACHE_DIR
@@ -35,8 +36,11 @@ install:
 before_script:
   - pip freeze | sort
 script:
+  # unshallow the clone so the conda build can clone it.
+  - git fetch --unshallow
   - IFS='.' read -r -a conda_npy_version <<< "$NUMPY_VERSION"
   - conda build conda/zipline --python=$TRAVIS_PYTHON_VERSION --numpy="${conda_npy_version[0]}.${conda_npy_version[1]}"  # accepts only major.minor
+
   - nosetests tests/
   - flake8 zipline tests
 after_success: