Worked on units

Units now stop when they get within attack range. Units now use sprite
sheets. Infantry range and size buffed.
Merge remote-tracking branch 'origin/master' into Units
Updated Unit Appearance
Merge remote-tracking branch 'origin/master' into Units

Conflicts:
	rts/src/buildings/towncenter.js
	rts/src/resource/buildingResources.js
	rts/src/rts.js
	rts/src/units/unit.js
Fixed errors in merge. However units don't render.
Finished fixing stuff
Merge pull request #10 from Jbtyson/Units

Merging Units into Master
Made it so buildings create hoplites
Merge pull request #11 from Jbtyson/Units

Merging Units into Master
fixing conflict in unit.js
Started implementing mining
Merge pull request #13 from Jbtyson/master

Merging Master into Units
Merge pull request #14 from Jbtyson/Units

Merging Units into Master
resolved conflicts