Pyyaml update 601 typo (#9)

* Update setup.py to use pyyaml 6.0.1. Update dls version to 2.2.2

* Update HISTORY.md and README.md for dls version 2.2.2

* Add detail to HISTORY.md about the security vulnerability requiring this update

* Fix typo

Author: ceckim

HISTORY.md

@@ -1,13 +1,14 @@
 ## Change Log
 
 ### 2.2.2
-Security Update: Updated PyYAML in setup.py to 6.0.1, due to a [security
-vulnerability](https://nvd.nist.gov/vuln/detail/CVE-2020-14343).
+
+Security Update: Updated PyYAML in setup.py to 6.0.1, due to a [security vulnerability](https://nvd.nist.gov/vuln/detail/CVE-2020-14343).
+
 
 ### 2.2.1
 
-Security Update: Updated PyYAML to 6.0.1 in requirements.txt only, due to a [security
-  5 vulnerability](https://nvd.nist.gov/vuln/detail/CVE-2020-14343).
+Security Update: Updated PyYAML to 6.0.1 in requirements.txt only, due to a [security vulnerability](https://nvd.nist.gov/vuln/detail/CVE-2020-14343).
+
 
 ### 2.2.0