fixed rxjs version

yarn.lock

@@ -738,11 +738,11 @@ rx-lite@*, rx-lite@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/rx-lite/-/rx-lite-4.0.8.tgz#0b1e11af8bc44836f04a6407e92da42467b79444"
 
-rxjs@^5.5.6:
-  version "5.5.6"
-  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-5.5.6.tgz#e31fb96d6fd2ff1fd84bcea8ae9c02d007179c02"
+rxjs@5.4.3:
+  version "5.4.3"
+  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-5.4.3.tgz#0758cddee6033d68e0fd53676f0f3596ce3d483f"
   dependencies:
-    symbol-observable "1.0.1"
+    symbol-observable "^1.0.1"
 
 safe-buffer@~5.1.0, safe-buffer@~5.1.1:
   version "5.1.1"
@@ -815,11 +815,7 @@ supports-color@^4.0.0:
   dependencies:
     has-flag "^2.0.0"
 
-[email protected]:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/symbol-observable/-/symbol-observable-1.0.1.tgz#8340fc4702c3122df5d22288f88283f513d3fdd4"
-
-symbol-observable@^1.0.2:
+symbol-observable@^1.0.1, symbol-observable@^1.0.2:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/symbol-observable/-/symbol-observable-1.1.0.tgz#5c68fd8d54115d9dfb72a84720549222e8db9b32"