Add Release Script (#358)

* Add Release Script

- Generates grpcwebproxy binaries for win, mac, and linux
- Uses `github-release` binary to do what it says on the tin and attach the grpcwebproxy binaries to the release
- Uses `lerna publish` to publish the client packages to npm

* - Add explicit check for github token in env
- Remove quotes from around bash glob as the github-release script will not expand globs.

* - Inline generate-grpcwebproxy-binaries.sh into publish-release.sh
- Fix hard-coded version strings in binary filenames
- Rename "build" folder to "dist"

* - Use `x86_64` suffix for binaries

* - Follow protoc binary filename conventions
- Zip all binaries

* Remove Travis publish step

We're going to try out github actions instead!

.travis.yml

@@ -61,12 +61,8 @@ script:
 stages:
   - lint
   - test
-  - deploy
 
 jobs:
   include:
     - stage: lint
-      script: ./lint-all.sh
-    - stage: deploy
-      if: tag =~ /^v[0-9]+\.[0-9]+\.[0-9]+$/
-      script: echo Releasing $TRAVIS_TAG
+      script: ./lint-all.sh

lint-all.sh

@@ -1,5 +1,4 @@
 #!/bin/bash
-
 set -e
 
 echo "Linting go sources"