Fix: Pegleg Exceptions docs rendering on RTD

Readthedocs failed to render Pegleg exceptions with error:
> WARNING: autodoc: failed to import exception ... from module
> 'pegleg'; the following exception was raised: No module named 'click'

Trying to add Pegleg requirements to the installed requirements list,
so that Readthedocs has all modules, including those needed for the
Pegleg itself.

Change-Id: I1780a9be3aeb0c3e2e775cbb1f713c2033f13e08

.readthedocs.yaml

@@ -0,0 +1,25 @@
+# .readthedocs.yml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: doc/source/conf.py
+
+# Build documentation with MkDocs
+#mkdocs:
+#  configuration: mkdocs.yml
+
+# Optionally build your docs in additional formats such as PDF and ePub
+formats:
+  - pdf
+
+# Optionally set the version of Python and requirements required to build your docs
+python:
+  version: 3.7
+  install:
+    - requirements: doc/requirements.txt
+    - requirements: requirements.txt

Makefile

@@ -103,6 +103,7 @@ docs: clean
 .PHONY: clean
 clean:
 	rm -rf build
+	rm -rf doc/build
 
 .PHONY: py_lint
 py_lint:

doc/source/exceptions.rst

@@ -17,42 +17,44 @@
 Pegleg  Exceptions
 ==================
 
+.. currentmodule:: pegleg.engine.exceptions
+
 Base Exceptions
 ---------------
 
-.. autoexception:: pegleg.engine.exceptions.PeglegBaseException
+.. autoexception:: PeglegBaseException
    :members:
    :undoc-members:
 
 Git Exceptions
 --------------
 
-.. autoexception:: pegleg.engine.exceptions.GitConfigException
+.. autoexception:: GitConfigException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GitException
+.. autoexception:: GitException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GitAuthException
+.. autoexception:: GitAuthException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GitProxyException
+.. autoexception:: GitProxyException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GitSSHException
+.. autoexception:: GitSSHException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GitInvalidRepoException
+.. autoexception:: GitInvalidRepoException
    :members:
    :show-inheritance:
    :undoc-members:
@@ -67,24 +69,24 @@ Authentication Exceptions
 PKI Exceptions
 --------------
 
-.. autoexception:: pegleg.engine.exceptions.IncompletePKIPairError
+.. autoexception:: IncompletePKIPairError
 
 Genesis Bundle Exceptions
 -------------------------
 
-.. autoexception:: pegleg.engine.exceptions.GenesisBundleEncryptionException
+.. autoexception:: GenesisBundleEncryptionException
    :members:
    :show-inheritance:
    :undoc-members:
 
-.. autoexception:: pegleg.engine.exceptions.GenesisBundleGenerateException
+.. autoexception:: GenesisBundleGenerateException
    :members:
    :show-inheritance:
 
 Passphrase Exceptions
 ---------------------
 
-.. autoexception:: pegleg.engine.exceptions.PassphraseCatalogNotFoundException
+.. autoexception:: PassphraseCatalogNotFoundException
    :members:
    :show-inheritance:
    :undoc-members: