Better cross platform builds (#118)

* Reverted Dockerfile to alpine base for quicker builds and smaller images

* Added CGO_ENABLED=0 to compile

.goreleaser.yml

@@ -5,6 +5,8 @@ project_name: outrigger-cli
 builds:
   - binary: rig
     main: ./cmd/main.go
+    env:
+      - CGO_ENABLED=0
     goos:
       - windows
       - darwin

Dockerfile

@@ -1,25 +1,20 @@
-FROM golang:1.9
+FROM golang:1.9-alpine
 
-# Install Ruby
-WORKDIR /tmp
-RUN apt-get -y update \
-    && apt-get -y install build-essential zlib1g-dev libssl-dev libreadline6-dev libyaml-dev
-RUN wget https://cache.ruby-lang.org/pub/ruby/2.4/ruby-2.4.2.tar.gz \
-    && tar xzf ruby-2.4.2.tar.gz \
-    && cd ruby-2.4.2 \
-    && ./configure --prefix=/usr/local \
-    && make \
-    && make install
+RUN apk add --no-cache \
+	ca-certificates \
+	git \
+	gcc \
+	libffi-dev \
+	make \
+	musl-dev \
+	rpm \
+	ruby \
+	ruby-dev \
+	tar
 
-# Install fpm for package building
-RUN apt-get install -y rpm \
-    && apt-get clean \
-    && rm -rf /var/lib/apt/lists \
-    && gem install --no-rdoc --no-ri fpm
-
-# Back to the Go thingies
-WORKDIR /go
 RUN go get -u github.com/golang/dep/... \
   && go get -u github.com/alecthomas/gometalinter \
   && go get -u github.com/goreleaser/goreleaser
+
 RUN gometalinter --install --update
+RUN gem install --no-rdoc --no-ri fpm

docker-compose.yml

@@ -23,6 +23,7 @@ services:
     environment:
       GOOS: ${GOOS:-darwin}
       GOARCH: ${GOARCH:-amd64}
+      CGO_ENABLED: 0
 
   # Install project dependencies.
   install: