Documentation: Adds a requirement.txt

In order to build the test documentation the python package `nose` is
required therefore this commit adds a requirements.txt to ensure the
package is available when building the documentation on RTD.

1 files changed, 1 insertions, 0 deletions

diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 00000000..f3c7e8e6
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +1 @@
+nose