Update html2canvas version

www/package-lock.json

@@ -2684,6 +2684,14 @@
         "hyphenate-style-name": "1.0.2"
       }
     },
+    "css-line-break": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/css-line-break/-/css-line-break-1.0.1.tgz",
+      "integrity": "sha1-GfIGOjPpX7KDG4ZEbAuAwYivRQo=",
+      "requires": {
+        "base64-arraybuffer": "0.1.5"
+      }
+    },
     "css-loader": {
       "version": "0.26.4",
       "resolved": "https://registry.npmjs.org/css-loader/-/css-loader-0.26.4.tgz",
@@ -4895,11 +4903,11 @@
       "integrity": "sha1-nSLgyjKsyVs/RbjVtPb73AWv/VU="
     },
     "html2canvas": {
-      "version": "1.0.0-alpha.4",
-      "resolved": "https://registry.npmjs.org/html2canvas/-/html2canvas-1.0.0-alpha.4.tgz",
-      "integrity": "sha1-t1Q+6kUkAHitGEesk5CBpXUYCho=",
+      "version": "1.0.0-alpha.8",
+      "resolved": "https://registry.npmjs.org/html2canvas/-/html2canvas-1.0.0-alpha.8.tgz",
+      "integrity": "sha1-LXxW+ErC43dnmdUBd0JrmLEb+ms=",
       "requires": {
-        "punycode": "2.1.0"
+        "css-line-break": "1.0.1"
       }
     },
     "htmlparser2": {

www/package.json

@@ -18,7 +18,7 @@
     "gatsby-source-filesystem": "^1.5.9",
     "gatsby-transformer-remark": "^1.7.23",
     "gzip-size": "^4.1.0",
-    "html2canvas": "1.0.0-alpha.4",
+    "html2canvas": "^1.0.0-alpha.8",
     "mkdirp": "^0.5.1",
     "typography": "^0.16.6",
     "typography-theme-github": "^0.15.10"