Move the required npm version to 6.0.1

Since moved to a npm 6 generated package-lock.json, bump the required
npm version to prevent churn in package-lock.json.

This is  a "advisory only", to enforce, the package.json would need
"engineStrict" : true,

http://www.marcusoft.net/2015/03/packagejson-and-engines-and-enginestrict.html

Fine that users build with npm 5 as long as they don't check in their
package-lock.json.

After downgrading to 5.6 and running npm install
bash-4.1$ git diff package-lock.json | wc -l
7913

Tested: "npm install && npm run build" with an npm 5.6, still builds.
Change-Id: I77899eabc1f6a450a40e005dd43404b034c31768
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/README.md b/README.md
index b0e1893..2b9b3b8 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ firmware stack. The WebUI uses AngularJS. Features include:
 
 ## Requirements
 nodejs (>= 4.2.6)
-npm (>= 5.6.0)
+npm (>= 6.0.1)
 
 **Note** The default installation of your Linux distro may not come with the
 required versions above. See the following for more information on updating:
diff --git a/package.json b/package.json
index 8b70827..0ae4c28 100644
--- a/package.json
+++ b/package.json
@@ -92,6 +92,6 @@
   ],
   "engines": {
     "node": ">=4.2.6",
-    "npm": ">=5.6.0"
+    "npm": ">=6.0.1"
   }
 }