Re-enable linting

[benbrown]

Fixes #727 #745

Description

This is an attempt to get linting re-enabled with a well tuned set of rules we can apply to both the core libraries and the samples and templates.

Specific Changes

• enable eslint with typescript extensions
• start with full set of recommended rules
• also apply the same or equivalent rules as those applied to javascript and typescript samples
• apply all automatic fixes
• add npm run eslint and npm run eslint-fix to root package

[coveralls]

Pull Request Test Coverage Report for Build #2086

• 241 of 271 (88.93%) changed or added relevant lines in 42 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.08%) to 87.444%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botbuilder/src/botFrameworkAdapter.ts	11	12	91.67%
libraries/botframework-config/src/botConfigurationBase.ts	1	2	50.0%
libraries/botframework-connector/src/auth/emulatorValidation.ts	3	4	75.0%
libraries/botbuilder-dialogs/src/dialogContext.ts	2	4	50.0%
libraries/botframework-connector/src/emulatorApiClient.ts	0	2	0.0%
libraries/botframework-config/src/botConfiguration.ts	2	5	40.0%
libraries/botframework-connector/src/auth/jwtTokenExtractor.ts	0	3	0.0%
libraries/botbuilder-core/src/showTypingMiddleware.ts	18	24	75.0%
libraries/botbuilder-azure/src/azureBlobTranscriptStore.ts	47	58	81.03%

Files with Coverage Reduction	New Missed Lines	%
libraries/botframework-config/src/botConfigurationBase.ts	2	85.59%

Totals
Change from base Build #2041:	-0.08%
Covered Lines:	3005
Relevant Lines:	3307

---

💛 - Coveralls

[benbrown]

for reference:
https://github.com/Microsoft/BotBuilder-Samples/blob/master/samples/javascript_typescript/02.a.echobot/tslint.json

https://github.com/Microsoft/BotBuilder-Samples/blob/master/samples/javascript_nodejs/02.a.echobot/.eslintrc.js

[benbrown]

When/before we merge this, we will need to change the build tests to run eslint instead of tslint. It currently fails.

[benbrown]

Now that the new set of tests are passing which includes running eslint instead of tslint, I think we can merge this and make those tests THE TESTS.

@cleemullins want to do the honors?