Implement Cobra CLI tooling, Viper config tooling (#336)

* start pulling out + replacing urfave and config

* replace many many instances of config

* move more stuff => viper

* properly remove urfave

* move some flags to root command

* add testrig commands to root

* alias config file keys

* start adding cli parsing tests

* reorder viper init

* remove config path alias

* fmt

* change config file keys to non-nested

* we're more or less in business now

* tidy up the common func

* go fmt

* get tests passing again

* add note about the cliparsing tests

* reorganize

* update docs with changes

* structure cmd dir better

* rename + move some files around

* fix dangling comma

vendor/gopkg.in/ini.v1/.golangci.yml

@@ -0,0 +1,21 @@
+linters-settings:
+  nakedret:
+    max-func-lines: 0 # Disallow any unnamed return statement
+
+linters:
+  enable:
+    - deadcode
+    - errcheck
+    - gosimple
+    - govet
+    - ineffassign
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
+    - nakedret
+    - gofmt
+    - rowserrcheck
+    - unconvert
+    - goimports