Merge pull request #121 from Denton-L/cache-build

Cache build

.travis.yml

@@ -20,8 +20,11 @@ deploy:
     branch: master
 env:
   global:
-  - ENCRYPTION_LABEL="b5c2730599da"
+    - ENCRYPTION_LABEL="b5c2730599da"
-  - COMMIT_AUTHOR_EMAIL="chris@ethereum.org"
+    - COMMIT_AUTHOR_EMAIL="chris@ethereum.org"
-  - COMMIT_AUTHOR="Travis CI"
+    - COMMIT_AUTHOR="Travis CI"
-  - PUSH_REPO="git@github.com:ethereum/browser-solidity.git"
+    - PUSH_REPO="git@github.com:ethereum/browser-solidity.git"
-  - FILES_TO_PACKAGE="assets background.js build icon.png index.html manifest.json README.md"
+    - FILES_TO_PACKAGE="assets background.js build icon.png index.html manifest.json README.md"
+cache:
+  directories:
+    - node_modules