Include full Python version in collect_env.py output (#59632)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59632
Before:
```
Python version: 3.7 (64-bit runtime)
```
After:
```
Python version: 3.7.7 (default, Mar 23 2020, 17:31:31) [Clang 4.0.1 (tags/RELEASE_401/final)] (64-bit runtime)
```
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: bdhirsh
Differential Revision: D28961500
Pulled By: ezyang
fbshipit-source-id: 0f95a49abf6977941f09a64243916576a820679f
