Add package-lock for npm

This fixes dependency issues that were experienced in notably #425 and
other master commits I've tried to restart on 12/08/17

.travis.yml

@@ -10,6 +10,9 @@ node_js:
   - '5'
   - '4'
 
+before_install:
+  - npm install -g npm
+
 install:
   - npm run dev-up
 

app/package-lock.json

@@ -0,0 +1,113 @@
+{
+  "name": "nativefier-placeholder",
+  "version": "1.0.0",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "electron-dl": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/electron-dl/-/electron-dl-1.8.0.tgz",
+      "integrity": "sha1-VmUtpVqv2kpwB09jE/33+UHsdSo=",
+      "requires": {
+        "pupa": "1.0.0",
+        "unused-filename": "0.1.0"
+      },
+      "dependencies": {
+        "pupa": {
+          "version": "1.0.0",
+          "resolved": "https://registry.npmjs.org/pupa/-/pupa-1.0.0.tgz",
+          "integrity": "sha1-mpVopa9+ZXuEYqbp1TKHQ1YM7/Y="
+        },
+        "unused-filename": {
+          "version": "0.1.0",
+          "resolved": "https://registry.npmjs.org/unused-filename/-/unused-filename-0.1.0.tgz",
+          "integrity": "sha1-5fM7yeSmP4f2TTwR0xl53vXS5/s=",
+          "requires": {
+            "modify-filename": "1.1.0",
+            "path-exists": "3.0.0"
+          },
+          "dependencies": {
+            "modify-filename": {
+              "version": "1.1.0",
+              "resolved": "https://registry.npmjs.org/modify-filename/-/modify-filename-1.1.0.tgz",
+              "integrity": "sha1-mi3sg4Bvuy2XXyK+7IWcoms5OqE="
+            },
+            "path-exists": {
+              "version": "3.0.0",
+              "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-3.0.0.tgz",
+              "integrity": "sha1-zg6+ql94yxiSXqfYENe1mwEP1RU="
+            }
+          }
+        }
+      }
+    },
+    "electron-window-state": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/electron-window-state/-/electron-window-state-4.1.1.tgz",
+      "integrity": "sha1-azT9wxs4UU3+yLfI97XUrdtnYy0=",
+      "requires": {
+        "deep-equal": "1.0.1",
+        "jsonfile": "2.4.0",
+        "mkdirp": "0.5.1"
+      },
+      "dependencies": {
+        "deep-equal": {
+          "version": "1.0.1",
+          "resolved": "https://registry.npmjs.org/deep-equal/-/deep-equal-1.0.1.tgz",
+          "integrity": "sha1-9dJgKStmDghO/0zbyfCK0yR0SLU="
+        },
+        "jsonfile": {
+          "version": "2.4.0",
+          "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-2.4.0.tgz",
+          "integrity": "sha1-NzaitCi4e72gzIO1P6PWM6NcKug=",
+          "requires": {
+            "graceful-fs": "4.1.11"
+          },
+          "dependencies": {
+            "graceful-fs": {
+              "version": "4.1.11",
+              "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.11.tgz",
+              "integrity": "sha1-Dovf5NHduIVNZOBOp8AOKgJuVlg=",
+              "optional": true
+            }
+          }
+        },
+        "mkdirp": {
+          "version": "0.5.1",
+          "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
+          "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
+          "requires": {
+            "minimist": "0.0.8"
+          },
+          "dependencies": {
+            "minimist": {
+              "version": "0.0.8",
+              "resolved": "https://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
+              "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0="
+            }
+          }
+        }
+      }
+    },
+    "source-map-support": {
+      "version": "0.4.14",
+      "resolved": "https://registry.npmjs.org/source-map-support/-/source-map-support-0.4.14.tgz",
+      "integrity": "sha1-nURjdyWYuGJxtPUj9sH04Cp9au8=",
+      "requires": {
+        "source-map": "0.5.6"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.5.6",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.6.tgz",
+          "integrity": "sha1-dc449SvwczxafwwRjYEzSiu19BI="
+        }
+      }
+    },
+    "wurl": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/wurl/-/wurl-2.1.0.tgz",
+      "integrity": "sha1-ciS9DmYuUTUiHSWdjWAUHC0T0xA="
+    }
+  }
+}