Fix Che dashboard build

[garagatyi]

Issue problem:
UD is no longer builds in RH-CHE (against latest snapshot) after the changes in latest upstream.
The error in build logs:

10:37:31      [exec] �[91mnpm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):
10:37:31      [exec] npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
10:37:31      [exec] �[0m�[91mnpm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.2.3 (node_modules/sane/node_modules/fsevents):
10:37:31      [exec] �[0m�[91mnpm WARN notsup�[0m�[91m SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
10:37:31      [exec] �[0m�[91mnpm WARN [email protected] requires a peer of [email protected] but none was installed.
10:37:31      [exec] �[0m�[91mnpm WARN�[0m�[91m [email protected] requires a peer of webpack@^2.0.0 || ^3.0.0 || ^4.0.0 but none was installed.
10:37:31      [exec] npm WARN [email protected] requires a peer of [email protected] but none was installed.
10:37:31      [exec] �[0m�[91mnpm WARN [email protected] No description
10:37:31      [exec] �[0m�[91mnpm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/bufferutil):
10:37:31      [exec] npm WARN optional�[0m�[91m SKIPPING OPTIONAL DEPENDENCY: [email protected] install: `node-gyp rebuild`
10:37:31      [exec] npm WARN optional�[0m�[91m SKIPPING OPTIONAL DEPENDENCY: Exit status 1
10:37:31      [exec] �[0m�[91mnpm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/utf-8-validate):
10:37:31      [exec] npm WARN�[0m�[91m optional SKIPPING OPTIONAL DEPENDENCY: [email protected] install: `node-gyp rebuild`
10:37:31      [exec] npm �[0m�[91mWARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status 1
10:37:31      [exec] �[0m�[91mnpm info ok 
10:38:05      [exec] �[0mRemoving intermediate container b7a543f6f86b
10:38:05      [exec]  ---> e00c0d4d021f
10:38:05      [exec] Step 6/10 : COPY ${SOURCES_DIR}/bower.json /dashboard/
10:38:05      [exec] COPY failed: stat /var/lib/docker/tmp/docker-builder279638829/target/sources/bower.json: no such file or 

Broken [here](https://github.com/eclipse-che/che/pull/11301/files): bower is removed, dockerfile is rewritten.

Red Hat Che version:

version: (help/about menu)

• I can reproduce it on latest official image

Reproduction Steps:

Describe how to reproduce the problem

Runtime:

runtime used:

• minishift (include output of minishift version)
• OpenShift.io
• Openshift Container Platform (include output of oc version)
• k8s (include output of kubectl version)

[amisevsk]

Would probably require just updating the assembly/fabric8-ide-dashboard-war/Dockerfile, as it copies bower.json explicitly.

[amisevsk]

I've created branch 6.13-SNAPSHOT to track necessary changes for building with upstream snapshot builds.

[amisevsk]

Fixed in PR #965

Closing as this issue is subsumed by #1001