Update Elixir to v1.12.3

[nelsonic]

This PR:

• Updates Elixir to v1.12.3 Elixir v1.12.3 #125
• Comments out unused code Fix Coverage (Investigate Why Below 100% ...) #126

@iteles please review/merge when you can.
My next step is to update the version of Phoenix and deploy to Fly.io dwyl/learn-devops#72
But I don't want to make this PR too big. 💭

[nelsonic]

Merge conflicts I need to resolve:

n@MBP hits % git pull origin master --rebase
remote: Enumerating objects: 43, done.
remote: Counting objects: 100% (43/43), done.
remote: Compressing objects: 100% (40/40), done.
remote: Total 40 (delta 24), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (40/40), 14.51 KiB | 200.00 KiB/s, done.
From github.com:dwyl/hits
 * branch            master     -> FETCH_HEAD
   971f459..3b51eb2  master     -> origin/master
Auto-merging test/support/conn_case.ex
CONFLICT (content): Merge conflict in test/support/conn_case.ex
Auto-merging test/support/channel_case.ex
CONFLICT (content): Merge conflict in test/support/channel_case.ex
Auto-merging mix.exs
CONFLICT (content): Merge conflict in mix.exs
Auto-merging lib/hits/application.ex
Auto-merging config/config.exs
CONFLICT (content): Merge conflict in config/config.exs
error: could not apply b33d9f7... upgrade to Phoenix 1.5.3 fixes issue #103
Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".
Could not apply b33d9f7... upgrade to Phoenix 1.5.3 fixes issue #103

[nelsonic]

Spot the conflict ... 🤷‍♂️

[nelsonic]

git rebase --continue
[detached HEAD b1ac67a] upgrade to Phoenix 1.5.3 fixes issue #103
 Author: nelsonic <[email protected]>
 4 files changed, 5 insertions(+), 3 deletions(-)
Auto-merging mix.lock
CONFLICT (content): Merge conflict in mix.lock
Auto-merging mix.exs
CONFLICT (content): Merge conflict in mix.exs
error: could not apply 681c393... upgrade all dependencies to latest versions #103
Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".
Could not apply 681c393... upgrade all dependencies to latest versions #103

[nelsonic]

Migrate to .com https://app.travis-ci.com/github/dwyl/hits

[codecov]

Codecov Report

Merging #127 (a741c5c) into master (971f459) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #127   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           11        11           
  Lines           62        63    +1     
=========================================
+ Hits            62        63    +1     

Impacted Files	Coverage Δ
lib/hits/application.ex	100.00% <ø> (ø)
lib/hits_web/channels/hit_channel.ex	100.00% <100.00%> (ø)

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[nelsonic]

@iteles if you have a couple of minutes, please review/merge this PR. Thanks. 👍

[iteles]

Sorry, I've been reviewing this slowly!

[nelsonic]

@iteles thanks. ☀️