Compile protos with protobuf.js

[Fixes #141]

.eslintignore

@@ -3,4 +3,4 @@ src/imp/platform/browser/thrift_api/crouton_types.js
 src/imp/platform/node/generated/crouton_types.js
 src/imp/platform/node/thrift_api/crouton_types.js
 src/imp/platform/node/crouton_thrift.js
-src/imp/generated_proto
+src/imp/generated_proto.js

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 *Log of significant changes, especially those affecting the supported API.*
 
+## Unreleased
+
+* Switch protobuf compilers to [protobuf.js](https://github.com/dcodeIO/ProtoBuf.js/).
+
 ## 0.21.0
 
 * Update `thrift` to `0.11.0`. This breaks support for node.js versions <= 5.8.

Makefile

@@ -5,6 +5,7 @@ recursive_wildcard = $(wildcard $1$2) $(foreach d,$(wildcard $1*),$(call recursi
 # build
 #
 CMD_BABEL=node node_modules/.bin/babel
+CMD_PROTO=node node_modules/.bin/pbjs
 CMD_WEBPACK=node node_modules/.bin/webpack
 SOURCES_JS=$(call recursive_wildcard,src/,*.js)
 COMPILED_JS=$(SOURCES_JS:src/%.js=lib/%.js)
@@ -142,6 +143,9 @@ thrift-postprocess:
 # LightStep internal target
 .PHONY: proto
 proto:
-	protoc -I"$(PWD)/../googleapis/:$(PWD)/../lightstep-tracer-common/" \
-		--js_out=import_style=commonjs,binary:src/imp/generated_proto \
-		collector.proto google/api/annotations.proto google/api/http.proto
+	$(CMD_PROTO) \
+		-p ../googleapis \
+		-p ../lightstep-tracer-common \
+		-t static-module \
+		--es6 \
+		../lightstep-tracer-common/collector.proto > src/imp/generated_proto.js