Fixes #110: Updating the dist from zip to .tar.gz

This will be used in the next release

Makefile

diff --git a/Makefile b/Makefile
index 6f6a9ac..7a09547 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@
 clean:
 	rm -f ./glide.test
 	rm -f ./glide
+	rm -rf ./dist
 
 bootstrap:
 	mkdir ./vendor
@@ -37,7 +38,7 @@
 	cd dist && \
 	$(DIST_DIRS) cp ../LICENSE.txt {} \; && \
 	$(DIST_DIRS) cp ../README.md {} \; && \
-	$(DIST_DIRS) zip -r glide-{}.zip {} \; && \
+	$(DIST_DIRS) tar -zcf glide-${VERSION}-{}.tar.gz {} \; && \
 	cd ..