update NEWS.md and version.py for 2.1.1 release (#778)

Author: Jasha10

NEWS.md

@@ -1,3 +1,14 @@
+## 2.1.1 (2021-08-17)
+### Features
+
+- Add a throw_on_missing keyword argument to the signature of OmegaConf.to_container, which controls whether MissingMandatoryValue exceptions are raised. ([#501](https://github.com/omry/omegaconf/issues/501))
+
+### Miscellaneous changes
+
+- Update pyyaml dependency specification for compatibility with PEP440 ([#758](https://github.com/omry/omegaconf/issues/758))
+- Fix a packaging issue (missing sdist dependency) ([#772](https://github.com/omry/omegaconf/issues/772))
+
+
 ## 2.1.0 (2021-06-07)
 
 

news/501.feature

@@ -1,6 +1,6 @@
 import sys  # pragma: no cover
 
-__version__ = "2.1.1.dev1"
+__version__ = "2.1.1"
 
 msg = """OmegaConf 2.0 and above is compatible with Python 3.6 and newer.
 You have the following options: