Add test-requirements file

.travis.yml

@@ -76,7 +76,7 @@ install:
           python setup.py bdist_wheel
           pip install $EXTRA_PIP_FLAGS dist/*.whl
       elif [ "$INSTALL_TYPE" == "requirements" ]; then
-          pip install $EXTRA_PIP_FLAGS -r requirements.txt
+          pip install $EXTRA_PIP_FLAGS -r test-requirements.txt
           pip install .
       fi
 

dev-requirements.txt

@@ -2,7 +2,6 @@
 # Use with:
 #   pip install -r dev-requirements.txt
 #
-# Include run-time requirements
--r requirements.txt
+# Include test requirements
+-r test-requirements.txt
 sympy
-pytest

test-requirements.txt

@@ -0,0 +1,8 @@
+# Runtime requirements for testing transforms3d
+# Use with:
+#   pip install -r test-requirements.txt
+#
+# Include run-time requirements
+-r requirements.txt
+scipy
+pytest