Initial implementation of SQLite3 connector

[kraman]

** This connector is based on postgresql connector

• Remove tests for unimplemented features
• Remove postgres related files
• Update tests to use sqlite3 format

Connect to https://github.com/strongloop-internal/scrum-nodeops/issues/409

[rmg]

@slnode test please

[raymondfeng]

LGTM

[rmg]

The tests are passing on CI, but this is in the console:

Deprecation warning: moment construction falls back to js Date. This is discouraged and will be removed in upcoming major release. Please refer to https://github.com/moment/moment/issues/1407 for more info.
Error
    at deprecate (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/moment/moment.js:738:42)
    at /mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/moment/moment.js:826:50
    at hookCallback (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/moment/moment.js:8:85)
    at Object.<anonymous> (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/moment/moment.js:11:2)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Object.Module._extensions.(anonymous function) [as .js] (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/build-framework/node_modules/istanbul/lib/hook.js:109:37)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/lib/sqlite3.js:9:509)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions.(anonymous function) [as .js] (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/build-framework/node_modules/istanbul/lib/hook.js:107:24)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/index.js:9:54)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions.(anonymous function) [as .js] (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/build-framework/node_modules/istanbul/lib/hook.js:107:24)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at global.getDataSource.global.getSchema (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/test/init.js:6:27)
    at Context.<anonymous> (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/test/sqlite.dbdefaults.test.js:10:10)
    at callFn (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/mocha/lib/runnable.js:266:21)
    at Hook.Runnable.run (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/mocha/lib/runnable.js:259:7)
    at next (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/mocha/lib/runner.js:271:10)
    at Object._onImmediate (/mnt/jenkins/workspace/loopback-connector-sqlite3.pr/eb78835e/node_modules/mocha/lib/runner.js:292:5)
    at processImmediate [as _immediateCallback] (timers.js:354:15)
[Error: Invalid date default: '5']

[kraman]

@rmg I am using moment to parse and check validity of the date being passed in. Do you know of a better library for that. I will merge but open an issue to address this.

[rmg]

This condition is inverted, which is why the test for an invalid default of '5' is passing. moment('5'), new Date('5') and Date.parse('5') all return ''Tue, 01 May 2001 07:00:00 GMT' or 988700400000 in epoch ms.

See #2