Add new summary tab to dashboard

[sjanuary]

Includes update to graphmetrics 1.1.0

[codecov-io]

Codecov Report

Merging #177 into master will decrease coverage by 0.13%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #177      +/-   ##
==========================================
- Coverage   16.57%   16.43%   -0.14%     
==========================================
  Files           8        8              
  Lines        1943     1959      +16     
==========================================
  Hits          322      322              
- Misses       1621     1637      +16

Flag	Coverage Δ
#SwiftBAMDC	0% <ø> (ø)	⬆️
#SwiftMetrics	16.43% <0%> (-0.14%)	⬇️
#SwiftMetricsBluemix	20.32% <ø> (ø)	⬆️
#SwiftMetricsDash	18.24% <0%> (-0.17%)	⬇️
#SwiftMetricsKitura	17.8% <0%> (-0.16%)	⬇️
#SwiftMetricsPrometheus	16.43% <0%> (-0.14%)	⬇️

Impacted Files	Coverage Δ
Sources/SwiftMetricsDash/SwiftMetricsDash.swift	0% <0%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1bb6e72...fe2caae. Read the comment docs.

[mattcolegate]

Changes look good, pulled and tested - summary tab comes up fine with good-looking data, came across issue where if you maximise the Environment pane, switch to the Dashboard tab then back to the Summary tab, the Environment pane is no longer central.

[sjanuary]

Fixed tab-switch bug in graphmetrics -RuntimeTools/graphmetrics#46
Updated submodule again to point to latest graphmetrics

[mattcolegate]

Change to graphmetrics fixes behaviour previously seen. Change approved so long as Travis builds