Dependencies updated for generated project

[UlisesGascon]

Generated project dependencies upgraded as requested in #759

 bootstrap           ^4.1.3  →   ^4.3.1 
 jquery              ^3.3.1  →   ^3.4.1 
 modernizr           ^3.6.0  →   ^3.7.1 
 popper.js          ^1.14.6  →  ^1.15.0 
 @babel/core         ^7.1.2  →   ^7.4.5 
 @babel/preset-env   ^7.1.0  →   ^7.4.5 
 autoprefixer        ^9.4.4  →   ^9.5.1 
 browser-sync        ^2.2.1  →  ^2.26.5 
 cssnano             ^4.1.7  →  ^4.1.10 
 del                 ^3.0.0  →   ^4.1.1 
 gulp                ^4.0.0  →   ^4.0.2 
 gulp-cli            ^2.0.1  →   ^2.2.0 
 gulp-filter         ^5.1.0  →   ^6.0.0 
 gulp-imagemin       ^5.0.3  →   ^6.0.0 
 gulp-load-plugins   ^1.2.4  →   ^1.6.0 
 gulp-plumber        ^1.0.1  →   ^1.2.1 
 gulp-sourcemaps     ^2.2.0  →   ^2.6.5 
 gulp-uglify         ^3.0.1  →   ^3.0.2 
 gulp-useref         ^3.0.0  →   ^3.1.6 
 mocha               ^5.2.0  →   ^6.1.4 
 yargs               12.0.5  →   13.2.4