Remove unused dependencies

These two dependencies were completely unused.

package.json

@@ -30,8 +30,6 @@
   },
   "homepage": "https://github.com/MetaMask/eth-sig-util#readme",
   "dependencies": {
-    "buffer": "^5.2.1",
-    "elliptic": "^6.4.0",
     "ethereumjs-abi": "^0.6.8",
     "ethereumjs-util": "^5.1.1",
     "tweetnacl": "^1.0.0",

yarn.lock

@@ -587,7 +587,7 @@ base64-js@^1.0.2:
   resolved "https://registry.yarnpkg.com/base64-js/-/base64-js-1.3.1.tgz#58ece8cb75dd07e71ed08c736abc5fac4dbf8df1"
   integrity sha512-mLQ4i2QO1ytvGWFWmcngKO//JXAQueZvwEKtjgQFM4jIK0kU+ytMfplL8j+n5mspOfjHwoAg+9yhb7BwAHm36g==
 
-base64-js@^1.2.3, base64-js@^1.3.1:
+base64-js@^1.2.3:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/base64-js/-/base64-js-1.5.1.tgz#1b1b440160a5bf7ad40b650f095963481903930a"
   integrity sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA==
@@ -909,22 +909,14 @@ buffer-xor@^1.0.3:
   resolved "https://registry.yarnpkg.com/buffer-xor/-/buffer-xor-1.0.3.tgz#26e61ed1422fb70dd42e6e36729ed51d855fe8d9"
   integrity sha1-JuYe0UIvtw3ULm42cp7VHYVf6Nk=
 
-buffer@^5.2.1:
-  version "5.5.0"
-  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.5.0.tgz#9c3caa3d623c33dd1c7ef584b89b88bf9c9bc1ce"
-  integrity sha512-9FTEDjLjwoAkEwyMGDjYJQN2gfRgOKBKRfiglhvibGbpeeU/pQn1bJxQqm32OD/AIeEuHxU9roxXxg34Byp/Ww==
+buffer@^5.5.0:
+  version "5.6.0"
+  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.6.0.tgz#a31749dc7d81d84db08abf937b6b8c4033f62786"
+  integrity sha512-/gDYp/UtU0eA1ys8bOs9J6a+E/KWIY+DZ+Q2WESNUA0jFRsJOc0SNUO6xJ5SGA1xueg3NL65W6s+NY5l9cunuw==
   dependencies:
     base64-js "^1.0.2"
     ieee754 "^1.1.4"
 
-buffer@^5.5.0:
-  version "5.7.1"
-  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.7.1.tgz#ba62e7c13133053582197160851a8f648e99eed0"
-  integrity sha512-EHcyIPBQ4BSGlvjB16k5KgAJ27CIsHY/2JBmCRReo48y9rQ3MaUzWX3KVlBa4U7MyX02HdVj0K7C3WaB3ju7FQ==
-  dependencies:
-    base64-js "^1.3.1"
-    ieee754 "^1.1.13"
-
 buffer@~5.2.1:
   version "5.2.1"
   resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.2.1.tgz#dd57fa0f109ac59c602479044dca7b8b3d0b71d6"
@@ -1637,7 +1629,7 @@ ee-first@1.1.1:
   resolved "https://registry.yarnpkg.com/ee-first/-/ee-first-1.1.1.tgz#590c61156b0ae2f4f0255732a158b266bc56b21d"
   integrity sha1-WQxhFWsK4vTwJVcyoViyZrxWsh0=
 
-elliptic@^6.0.0, elliptic@^6.4.0, elliptic@^6.5.2:
+elliptic@^6.0.0, elliptic@^6.5.2:
   version "6.5.3"
   resolved "https://registry.yarnpkg.com/elliptic/-/elliptic-6.5.3.tgz#cb59eb2efdaf73a0bd78ccd7015a62ad6e0f93d6"
   integrity sha512-IMqzv5wNQf+E6aHeIqATs0tOLeOTwj1QKbRcS3jBbYkl5oLAserA8yJTT7/VyHUYG91PRmPyeQDObKLPpeS4dw==
@@ -2643,11 +2635,6 @@ iconv-lite@0.4.24, iconv-lite@^0.4.24:
   dependencies:
     safer-buffer ">= 2.1.2 < 3"
 
-ieee754@^1.1.13:
-  version "1.2.1"
-  resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.2.1.tgz#8eb7a10a63fff25d15a57b001586d177d1b0d352"
-  integrity sha512-dcyqhDvX1C46lXZcVqCpK+FtMRQVdIMN6/Df5js2zouUsqG7I6sFxitIC+7KYK29KdXOLHdu9zL4sFnoVQnqaA==
-
 ieee754@^1.1.4:
   version "1.1.13"
   resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.1.13.tgz#ec168558e95aa181fd87d37f55c32bbcb6708b84"