Update to Angular 7.0.4

[gregmagolan]

This is depending on a material2 commit (angular/components#14143) that fixes the version skew in @angular/bazel in the material 7.0.4 release. This should be merged into angular/material2 shortly.

Rules sass update needed to be compatible with material repo.

[gregmagolan]

Not sure why CI isn't running? @alexeagle You may have to configure CircleCI to run CI on PRs?

[buildsize]

File name	Previous Size	New Size	Change
bundle.min.js	474 bytes	474 bytes	0 bytes (0%)
hello-world.module.ngfactory.js	12.43 KB	12.43 KB	0 bytes (0%)
hello-world.module.ngfactory.js.map	28.07 KB	28.07 KB	0 bytes (0%)
todos.module.ngfactory.js	19.02 KB	19.02 KB	0 bytes (0%)
todos.module.ngfactory.js.map	43.98 KB	43.98 KB	0 bytes (0%)
main.js	22.39 KB	22.39 KB	0 bytes (0%)
main.js.map	45.84 KB	45.84 KB	0 bytes (0%)
chunk.js	1.7 MB	1.64 MB	-66.25 KB (4%)
chunk.js.map	5.31 MB	5.26 MB	-50.05 KB (1%)
chunk2.js	15.21 KB	15.21 KB	0 bytes (0%)
chunk2.js.map	44.5 KB	44.5 KB	0 bytes (0%)