Create Salt Block

[jpoetker]

As Steve I want to mine salt blocks from the beach biome so that I can gather salt (Sodium & Chlorine).

• [x] Verify that salt blocks generate in the beach biome
• [x] Verify that the salt blocks do not generate in other biomes
• [x] Verify that breaking salt block drops salt item
• [x] Verify that salt block shows up in proper creative tab and has proper properties
• [x] Verify that salt block has a unique salt texture