adds React Boston 2019 to conference page (#1948)

* add React Boston 2019 to conference page

* add massachusetts to react-boston listing

content/community/conferences.md

@@ -72,6 +72,11 @@ September 13th, 2019. New York, USA
 
 [Website](https://reactnewyork.com/) - [Twitter](https://twitter.com/reactnewyork)
 
+### React Boston 2019 {#react-boston-2019}
+September 21-22, 2019 in Boston, Massachusetts USA
+
+[Website](https://www.reactboston.com/) - [Twitter](https://twitter.com/reactboston)
+
 ### React India 2019 {#react-india-2019}
 September 26-28, 2019 in Goa, India
 
@@ -379,4 +384,4 @@ April 4-5, 2019 in Kraków, Poland
 ### React Amsterdam 2019 {#react-amsterdam-2019}
 April 12, 2019 in Amsterdam, The Netherlands
 
-[Website](https://react.amsterdam) - [Twitter](https://twitter.com/reactamsterdam) - [Facebook](https://www.facebook.com/reactamsterdam) - [Videos](https://youtube.com/c/ReactConferences)
+[Website](https://react.amsterdam) - [Twitter](https://twitter.com/reactamsterdam) - [Facebook](https://www.facebook.com/reactamsterdam) - [Videos](https://youtube.com/c/ReactConferences)