Merge #26: Make WASM compatible

970b841 Cargo: Make WASM compatible (Christian Lewe)
aae8139 Cargo: Remove lazy_static (Christian Lewe)

Pull request description:

  Use the latest rust-simplicity master which is compatible with WASM. The version on crates.io is not yet compatible.

  Depends on BlockstreamResearch/rust-simplicity#214

ACKs for top commit:
  apoelstra:
    ACK 970b841

Tree-SHA512: 95c5df1cddc51d57a12bff7a6cbe69848be768d3f101eba58e88444a2ed562dcd6d61da22e5fca6b8d0957e0863afc6cd4cc10edc8dad6f234403c2780e60281

Author: uncomputable