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

internal/processing/streaming/streaming_test.go

@@ -38,11 +38,13 @@ type StreamingTestSuite struct {
 }
 
 func (suite *StreamingTestSuite) SetupTest() {
+	testrig.InitTestLog()
+	testrig.InitTestConfig()
+
 	suite.testAccounts = testrig.NewTestAccounts()
 	suite.testTokens = testrig.NewTestTokens()
 	suite.db = testrig.NewTestDB()
 	suite.oauthServer = testrig.NewTestOauthServer(suite.db)
-	testrig.InitTestLog()
 	suite.streamingProcessor = streaming.New(suite.db, suite.oauthServer)
 
 	testrig.StandardDBSetup(suite.db, suite.testAccounts)