Warnings and import errors when generating docs
🐛 Bug
There are many warnings when generating the docs, many are import failures.
Because of them, the Trainer docs disappeared, see here: https://pytorch-lightning.readthedocs.io/en/latest/trainer.html
To Reproduce
Steps to reproduce the behavior:

cd docs
make clean
make html

WARNING: autodoc: failed to import module 'pl_examples'; the following exception was raised:
Traceback (most recent call last):
  File "d:\anaconda3\envs\lightning\lib\site-packages\sphinx\ext\autodoc\importer.py", line 32, in import_module
    return importlib.import_module(modname)
  File "d:\anaconda3\envs\lightning\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\aeduw\Documents\Repositories\pytorch-lightning\pl_examples\__init__.py", line 143, in <module>
    from .basic_examples.lightning_module_template import LightningTemplateModel
  File "C:\Users\aeduw\Documents\Repositories\pytorch-lightning\pl_examples\basic_examples\lightning_module_template.py", line 21, in <module>
    class LightningTemplateModel(pl.LightningModule):
AttributeError: module 'pytorch_lightning' has no attribute 'LightningModule'

Expected behavior
no import errors.
Environment
PyTorch version: 1.4.0
Is debug build: No
CUDA used to build PyTorch: 10.1
OS: Microsoft Windows 10 Pro
GCC version: Could not collect
CMake version: Could not collect
Python version: 3.7
Is CUDA available: Yes
CUDA runtime version: Could not collect
GPU models and configuration: GPU 0: GeForce GTX 1070
Nvidia driver version: 442.19
cuDNN version: Could not collect
Versions of relevant libraries:
[pip] numpy==1.18.1
[pip] pytorch-lightning==0.6.1.dev0
[pip] torch==1.4.0
[conda] blas                      1.0                         mkl
[conda] mkl                       2020.0                      166
[conda] mkl-service               2.3.0            py37hb782905_0
[conda] mkl_fft                   1.0.15           py37h14836fe_0
[conda] mkl_random                1.1.0            py37h675688f_0
[conda] pytorch                   1.4.0           py3.7_cuda101_cudnn7_0    pytorch
[conda] pytorch-lightning         0.6.1.dev0                dev_0    
Additional context