chore(yarn, lerna): update yarn and lerna

bring travis to the same version of yarn (1.2.1) where the jest workaround dont work anymore

.travis.yml

@@ -14,7 +14,7 @@ cache:
         - node_modules
 
 before_install:
-  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.0.2
+  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.2.1
   - export PATH="$HOME/.yarn/bin:$PATH"
 
 install:

lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "2.2.0",
+  "lerna": "2.4.0",
   "packages": ["packages/*"],
   "version": "independent",
   "command": {

package.json

@@ -71,13 +71,13 @@
     "flow-typed": "^2.1.5",
     "jest": "^21.2.1",
     "jest-enzyme": "^4.0.0",
-    "lerna": "^2.3.1",
+    "lerna": "^2.4.0",
     "lint-staged": "^4.2.3",
     "prettier": "^1.7.4",
     "prop-types": "^15.6.0",
     "react": "^16.0.0",
     "react-dom": "^16.0.0",
-    "react-test-renderer": "16",
+    "react-test-renderer": "^16.0.0",
     "styled-components": "^2.2.1"
   }
 }

yarn.lock

@@ -5089,7 +5089,7 @@ lcov-parse@^0.0.10:
   version "0.0.10"
   resolved "https://registry.yarnpkg.com/lcov-parse/-/lcov-parse-0.0.10.tgz#1b0b8ff9ac9c7889250582b70b71315d9da6d9a3"
 
-lerna@^2.3.1:
+lerna@^2.4.0:
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/lerna/-/lerna-2.4.0.tgz#7b76446b154bafb9cba8996f3dc233f1cb6ca7c3"
   dependencies:
@@ -6802,7 +6802,7 @@ react-style-proptype@^3.0.0:
   dependencies:
     prop-types "^15.5.4"
 
-react-test-renderer@16:
+react-test-renderer@^16.0.0:
   version "16.0.0"
   resolved "https://registry.yarnpkg.com/react-test-renderer/-/react-test-renderer-16.0.0.tgz#9fe7b8308f2f71f29fc356d4102086f131c9cb15"
   dependencies: