Add a script requirements file to upgrade automation.

The xblock counting script had a requirements file that was not
previously being tracked and had an out of date version of requests.
Add it to the `upgrade` make target so that it stays up to date.

Makefile

@@ -63,7 +63,8 @@ REQ_FILES = \
 	requirements/edx-sandbox/base \
 	requirements/edx/base \
 	requirements/edx/testing \
-	requirements/edx/development
+	requirements/edx/development \
+	scripts/xblock/requirements
 
 upgrade: export CUSTOM_COMPILE_COMMAND=make upgrade
 upgrade: ## update the pip requirements files to use the latest releases satisfying our constraints

requirements/edx/base.txt

@@ -246,3 +246,6 @@ xblock-utils==1.2.1
 xblock==1.2.2
 xmlsec==1.3.3             # via python3-saml
 zendesk==1.1.1
+
+# The following packages are considered to be unsafe in a requirements file:
+# setuptools==41.0.1        # via fs, lazy, python-levenshtein

requirements/edx/development.txt

@@ -335,3 +335,6 @@ xmlsec==1.3.3
 xmltodict==0.12.0
 zendesk==1.1.1
 zipp==0.5.1
+
+# The following packages are considered to be unsafe in a requirements file:
+# setuptools==41.0.1        # via caniusepython3, fs, lazy, pytest, python-levenshtein, sphinx, tox

requirements/edx/paver.txt

@@ -27,3 +27,6 @@ stevedore==1.30.1
 urllib3==1.23             # via requests
 watchdog==0.9.0
 wrapt==1.10.5
+
+# The following packages are considered to be unsafe in a requirements file:
+# setuptools==41.0.1        # via lazy

requirements/edx/testing.txt

@@ -321,3 +321,6 @@ xmlsec==1.3.3
 xmltodict==0.12.0         # via moto
 zendesk==1.1.1
 zipp==0.5.1               # via importlib-metadata
+
+# The following packages are considered to be unsafe in a requirements file:
+# setuptools==41.0.1        # via caniusepython3, fs, lazy, pytest, python-levenshtein, tox

scripts/xblock/requirements.in

+requests

scripts/xblock/requirements.txt

-requests==2.10.0
+#
+# This file is autogenerated by pip-compile
+# To update, run:
+#
+#    make upgrade
+#
+certifi==2019.3.9         # via requests
+chardet==3.0.4            # via requests
+idna==2.8                 # via requests
+requests==2.22.0
+urllib3==1.25.3           # via requests