add support for extracting elapsed time from the omexml

[tlnagy]

Closes #27

• [x] Need tests

Example:

julia> img = load("migrating_hl60s_gems_preosmo_1_MMStack.ome.tif");

julia> img["Elapsed_Times"]
1000-element AxisArrays.AxisArray{Unitful.Quantity{Float64,𝐓,Unitful.FreeUnits{(s,),𝐓,nothing}},1,Array{Unitful.Quantity{Float64,𝐓,Unitful.FreeUnits{(s,),𝐓,nothing}},1},Tuple{AxisArrays.Axis{:time,UnitRange{Int64}}}}:
              2.422 s
              2.437 s
 2.4600100097656252 s
  2.479010009765625 s
  2.502010009765625 s
  2.521010009765625 s
  2.544010009765625 s
  2.563010009765625 s
  2.586010009765625 s
 2.6050100097656252 s
   2.62802001953125 s
   2.64702001953125 s
   2.67002001953125 s
   2.68902001953125 s
 2.7120200195312503 s
   2.73102001953125 s
   2.75002001953125 s
   2.77302001953125 s
   2.79202001953125 s
  2.815030029296875 s
  2.834030029296875 s
  2.857030029296875 s
 2.8760300292968752 s
  2.899030029296875 s
  2.918030029296875 s
  2.941030029296875 s
  2.960030029296875 s

[codecov[bot]]

Codecov Report

Merging #33 into master will decrease coverage by 0.55%. The diff coverage is 90%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
- Coverage   93.93%   93.38%   -0.56%     
==========================================
  Files           5        5              
  Lines         231      257      +26     
==========================================
+ Hits          217      240      +23     
- Misses         14       17       +3

Impacted Files	Coverage Δ
src/loader.jl	93.75% <80%> (-1.34%)	:arrow_down:
src/parsing.jl	96.96% <92%> (-3.04%)	:arrow_down:

---

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 9b7a431...60620d9. Read the comment docs.

[codecov[bot]]

Codecov Report

Merging #33 into master will decrease coverage by 0.55%. The diff coverage is 90%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
- Coverage   93.93%   93.38%   -0.56%     
==========================================
  Files           5        5              
  Lines         231      257      +26     
==========================================
+ Hits          217      240      +23     
- Misses         14       17       +3

Impacted Files	Coverage Δ
src/loader.jl	93.75% <80%> (-1.34%)	:arrow_down:
src/parsing.jl	96.96% <92%> (-3.04%)	:arrow_down:

---

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 9b7a431...60620d9. Read the comment docs.

[codecov[bot]]

Codecov Report

Merging #33 into master will decrease coverage by 0.55%. The diff coverage is 90%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
- Coverage   93.93%   93.38%   -0.56%     
==========================================
  Files           5        5              
  Lines         231      257      +26     
==========================================
+ Hits          217      240      +23     
- Misses         14       17       +3

Impacted Files	Coverage Δ
src/loader.jl	93.75% <80%> (-1.34%)	:arrow_down:
src/parsing.jl	96.96% <92%> (-3.04%)	:arrow_down:

---

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 9b7a431...e0a3f1f. Read the comment docs.