Make generation of demo.svg deterministic (#625)

.travis.yml

@@ -1,12 +1,16 @@
-sudo: false
 language: go
 go:
   - 1.11.x
   - 1.12.x
 
+env:
+  global:
+    - NODE_VERSION=10.15.0
+
 before_script:
   - go get github.com/valyala/quicktemplate # for tests
   - go get github.com/pkg/errors # for tests
+  - nvm install "${NODE_VERSION}"
 
 script: make check_generated test
 

Makefile

@@ -69,7 +69,7 @@ tools/godownloader: Makefile tools/go.mod
 
 tools/svg-term:
 	@mkdir -p tools
-	cd tools && npm install svg-term-cli
+	cd tools && npm ci
 	ln -sf node_modules/.bin/svg-term $@
 
 tools/Dracula.itermcolors:

tools/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "svg-term-cli": "2.1.1"
+  }
+}