Repository: open-telemetry/opentelemetry-python

Issue:
ReadTheDocs configuration issue
The RTD documentation is not updated with my changes in #1096 https://opentelemetry-python.readthedocs.io/en/latest/sdk/resources.html

However, it works fine locally.

**Steps to reproduce**
Reproduced in all builds on RTD. For example, see logs here: https://readthedocs.org/projects/opentelemetry-python/builds/11937984/ (all builds [here](https://readthedocs.org/projects/google-cloud-opentelemetry/builds/))

You can run the commands in the logs to repro locally and see many of these types of errors:
```
WARNING: autodoc: failed to import module 'zipkin' from module 'opentelemetry.exporter'; the following exception was raised:
Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/site-packages/sphinx/ext/autodoc/importer.py", line 32, in import_module
    return importlib.import_module(modname)
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/checkouts/latest/exporter/opentelemetry-exporter-zipkin/src/opentelemetry/exporter/zipkin/__init__.py", line 72, in <module>
    from opentelemetry.sdk.trace.export import SpanExporter, SpanExportResult
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/checkouts/latest/opentelemetry-sdk/src/opentelemetry/sdk/__init__.py", line 19, in <module>
    from . import metrics, trace, util
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/checkouts/latest/opentelemetry-sdk/src/opentelemetry/sdk/metrics/__init__.py", line 33, in <module>
    from opentelemetry.sdk.resources import Resource
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/checkouts/latest/opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py", line 98, in <module>
    OPENTELEMETRY_SDK_VERSION = pkg_resources.get_distribution(
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/site-packages/pkg_resources/__init__.py", line 481, in get_distribution
    dist = get_provider(dist)
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/site-packages/pkg_resources/__init__.py", line 357, in get_provider
    return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/site-packages/pkg_resources/__init__.py", line 900, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/docs/checkouts/readthedocs.org/user_builds/opentelemetry-python/envs/latest/lib/python3.8/site-packages/pkg_resources/__init__.py", line 786, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'opentelemetry-sdk' distribution was not found and is required by the application
```

**What is the expected behavior?**
<img width="1218" alt="Screen Shot 2020-09-22 at 3 23 21 PM" src="https://user-images.githubusercontent.com/1510004/93927952-9410df00-fce7-11ea-9328-2d4c9951089e.png">

**What is the actual behavior?**
See logs above



Discussion:

Resolving patch:
diff --git a/docs/conf.py b/docs/conf.py
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -25,8 +25,6 @@
 
 
 source_dirs = [
-    os.path.abspath("../opentelemetry-api/src/"),
-    os.path.abspath("../opentelemetry-sdk/src/"),
     os.path.abspath("../opentelemetry-instrumentation/src/"),
 ]
 


Test patch: